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hitnmiss
07-24-2008, 11:58 AM
So my dad is retired and tends to shop CD rates to put a little money in. When looking for investments he found that with tax incentives and rebates solar photo voltaic is an attractive investment.

Don't know the exact numbers but seems the install will cost him about $12,000

Apparently the state of CO passed a law that says the power companies have to have X% of renewable energy in place by a certain date and one way the power companies are doing it is to subsidize house installs of PV cells.

My dads house is pretty big 3,000ft^2 ranch with 1/2 finished basement. Gas heat, and Air conditioned. The system is sized to provide about 100% of their electrical needs. Up to the power your house uses you get rebated at residential rates, above that you only get what the electric company buys electricity at so it doesn't pay to make more than your yearly home use.

The system will be about 900sq feet. My dad figured it will pay off in 10 years and the cells are guaranteed for 25. They are designed to withstand 1" hail and insurance will cover hail damage.

I think it's very cool. I'd much rather pay for this system than send my money to the middle east and have kids dying for oil. (not that this is a total solution I understand but its a step)

I have a question:

I've read (here?) that PV cells never generate the energy it took to make them. I find that hard to believe, how can a mere 900ft^2 of anything take 25 years of an AC'd house worth of energy to make?

J Tiers
07-25-2008, 12:46 AM
To get that calculation to work is the usual "global" costing....

The total energy cost of the factory that built the cells, the energy cost of the extra equipment to make the materials of which the factory is composed, minimg sufficient ore to make the steel, everything down to the gas to take the bank guy to lunch getting the loan for the factory....... energy cost to take out the trash at the factory, and gas for the workers to get there...it is all included.

Then the lifetime of the cells is arbitrarily put at about 1/3 of the actual.

Taken that way, it may very well be that the energy is never recouped.

The problem with that type calculation is that it is wrong on several levels.

For one obvious point, it assumes that everything is "used up" and has no scrap value..... i.e. the steel in all the buildings and equipment is counted as "destroyed", the buildings are counted as non-re-usable, even water used in the processes is counted as "destroyed" after use (must be a lot of gamma rays comoing out around there).

The fallacy in that sort of calculation is that material and refining it is not "lost energy" when the materials are no longer of use in their original form, there is scrap value and melting scrap uses less energy than making new steel from ore. buildings can be re-used, whether they actually are or not, water is typically cleaned at the sewage plant and returned to the environment.

So many of the energy costs are not really totally allocatable to that use as a PV cell factory.

Plus, what type of PV is being discussed?

Old-time single crystal cells? Polycrystalline cells? Thin film amorphous? Space qualified or commercial?

Energy costs are dramatically different for the different types, yield rates are dramatically different for the different types, and a calculation for the most energy-intensive types is bogus when applied to a different type.

JRouche
07-25-2008, 01:06 AM
Twelve grand is about half as much as I have researched for a system for my house. I also have a 3000 sqft house. Mine is in So Cal but I dont need A/C being by the coast, I dont have it now. And heat is also nil.

But just going off of what I consume, and its been constant for the last five years, although the bill hasent LOL.

I crunched the numbers for myself and I could not recoup the outlay. It would take me twenty years to recoup the cost, just to break even and start enjoying the benefits from solar. And that was assuming all the equipment was service free, meaning it would not have any failures.

Just didnt add up for me. Specially if I considered the $24,000 if I placed it in a low bearing account and just removed the normal electric bill monthly from it. I would loose money by sinking it into a whole house system. I ran the numbers many times, not cost effective for me. JR

J Tiers
07-25-2008, 01:20 AM
You might check again assuming an electric bill 3x what yours is now.......

I know folks who did their system for $5000, but they have limited needs...... used to have only a generator or kero lamps. :eek:

hitnmiss
07-25-2008, 08:28 AM
The 12k price was after some pretty attractive rebates. I think the actual cost is around 40K.

Still, give it 5 more years and the actual cost is 12K and electricity has tripled...

It's kinda cool because my dad is no tree hugger and yet it just made financial sense.

Don't know the type of cell, I'll ask next time I'm down there.

Evan
07-25-2008, 09:15 AM
My dad installed Grumman solar water panels on his house back in the 60s. They still operate just fine. He has a big house and usually rents out several rooms to students so there are a lot of showers and hot water use. In the basement is a 200 gallon well insulated hot water tank. As he lives in Berkeley there is plenty of sunshine a lot of the year. I don't recall how much the system cost but over the last 45 years or so it has probably paid for itself many times.

The hidden cost of PV cells is enormous. To make silicon polycrystalline or especially monocrystalline cells requires the same infrastructure as making silicon chips up to a point. Just the machines to pull the silicon ingots are incredibly expensive. I don't know what a solar cell fabrication foundry costs but a silicon chip fab can start at 1/2 billion to over a billion dollars. The processes used are also extremely energy intensive as the first steps are purifying and melting the silicon, a process similar to making glass except it is done in very small batches compared to glass making. Subsequent steps also involve baking at high temperatures to infuse dopant elements into the silicon. The only cheap part of the process is the raw material, sand.

hitnmiss
07-25-2008, 10:44 AM
I wonder what the hidden costs of oil, natural gas and coal are...

Not defending solar pv, I'm looking for data.

Shipping troops to the middle east cost billions, and oil is still plentiful. Wait till there are actual shortages.

Gotta do something. I don't see the government laying down plans.

I fear the next war for oil will be 10x this one.

dsergison
07-25-2008, 11:08 AM
if is sounds to good to be true.....

look at it this way.

manufactures are at capacity producing these cells.

they price them at the ragged edge of ROI.

if it actually paid back in 5 years it would be the greatest investment.
I think they price them at the 20 year mark.

/I could be full of crap, but I just priced a system myself, that's what I found.

Evan
07-25-2008, 12:15 PM
You have seen the issue that Evan prefers to ignore.

The alternatives (basically coal burning) we have at present INCREASE THE RETENTION OF HEAT, AND WILL CONTINUE TO INCREASE IT, SPIRALING UPWARDS IN RETENTION AS LONG AS WE CONTINUE TO USE THEM.
And solar cells capture excess heat as long as they are in use. The problem is they CAPTURE HEAT THAT WOULDN'T BE CAPTURED OTHERWISE.

The PV alternative is ONE (among others) which offsets not only the direct heating (2x power generated, net) caused by burning coal, BUT ALSO THE LINGERING EFFECTS OF THAT COAL BURNING ON THE RETENTION OF SOLAR GAIN FROM ALL OTHER "CAUSES", BE THEY EVAN'S "BLACK" SOLAR CELLS OR BLACK ROCKS, DIRT, TREES, OR THE OCEANS*.

They are not MY solar cells Jerry, they are the latest and "greatest" idea in solar technology. It also doesn't matter which apparent color they are. The apparent color of a solar cell is narrow bandwidth reflection. All the other bands are absorbed. That is on purpose.

it is important to remember that the coal alternative increases the retention of heat WORLDWIDE, heating due to land area, oceans, cities, or solar cells. it is not just "local" in effect.

Same as with the heat retained with solar cells.

Evan and others keep harping on the idea that solar cells (using monocrystalline silicon as the model cell, and only possible cell) "can never pay back their huge energy cost and the horrible chemicals used to diffuse the junction into the silicon"... He ignores the newer technologies which allow cells to be "printed" by the tens of square meters at a time, with less obnoxious chemicals and much less energy input.

I'm not even talking about monocrystalline solar cells at all. I am specifically talking about those newer printed cells. That is what the picture I posted is about, the Nanosolar product.

They also ignore the fact that the existing electric power grid has yet to (and can never), generate enough power to make the materials used in IT.

I never mentioned any "horrible chemicals". The diffusion process is extremely energy intensive.

"Hand waving" or not, a simple qualitative look suggests that there are three alternatives......aside from nuclear power, which has already been effectively taken off the table.

More handwaving about handwaving?

1) stop using power, and go back towards pre-industrial life, accepting the massive human die-off that results. This is the alternative that most traditional environmentalists prefer, whether they admit it or not.

2) keep burning coal (stored solar power), which will keep INCREASING the heat retention per watt of solar gain, and raise the earth's temperature. This seems to be Evan's "solution", even though he has already accepted and endorsed the fact that it does and will continue to cause heating, at a steadily increasing rate.

Don't make assumptions. Coal is a very dirty way to make power. reducing consumption is much better and is also extremely doable. Putting a light colored roof on my house has cooled the interior considerably in the current hot weather. I don't have air conditioning and don't need it even when it is around 100f outside.

3) use alternative means of converting solar power (in it's various forms) to usable power, even if SOME of them DO cause a minute increase in the global average heat input. Keep working on increasing the efficiency of these means so that the effect is minimized**. Add some other means such as geothermal etc, if and as they become more widely usable.

The estimated area required to supply the USA from solar power alone is 100,000 sq miles of solar cells. If they trap an excess of 2 kilowatts of heat per hour per sq meter over 3000 hrs per year of sunshine the numbers are staggering. 2,589,988 sq meters per sq mile x 3000 hrs per year x 2 kilowatts x 100,000 sq miles=1,553,992,800,000,000,000 excess watts per year trapped.
That's 1.5 EXAWATTS. It is also, not coincidentally, the same as TWO TIMES the current total energy consumption of the USA, the largest consumer on the earth. This is not "a minute increase in global output".


it seems obvious that alternative "2" is not a "solution" which will solve anything, regardless of Evan's roof. I can't imagine ANYONE who can think supposing it is worth considering, unless they deny the effect altogether.

Alternative "1" will work fine, but may not be very acceptable, since once the environmentalists have all shot themselves to save the planet, the rest will keep right on going as they are until they do it to themselves with a big mess.

* The oceans, by far the dominant feature of the earth's surface, are about the same blue color from space as the usual silicon solar cell.

One might, with Evan's logic, suppose they reflect about the same amount of energy...... so much for the heating. If we covered the earth 100% with that color, we would logically not equal what the oceans now already absorb, as they have more surface area than the land.

The oceans are excellent absorbers of heat. You are misleading yourself and others by thinking that the reflection of a single color of light equates to the reflection of a large amount of energy. It doesn't. Ever notice how an antireflection lens coating looks BLUE?

If we covered the land with something that absorbed the same as the oceans do we would have to use something like solar cells. Oops.

** One would accurately presume that ideal solar cells , which are what is being worked on, would be efficient. Clearly, the more efficient the cell, the fewer are needed, and the smaller the amount of area covered by them. Doubling the efficiency halves the area used........ Obviously that is of benefit, even if only on an economic basis.

But, we don't have ideal solar cells. Real world efficiency one they are enclosed in slightly dirty glass frames is maybe 10% at best.

Your Old Dog
07-25-2008, 02:13 PM
Color me stupid I guess but if the wars we fight are for oil, why the hell are we paying $4+ for gas and $5+ for diesel? I don't get it.

I'd like to do solar myself but not to save the planet. I'd just like to do it out of curiosity. I will do solar on my RV and take great fun in watching it all work.

andy_b
07-25-2008, 02:20 PM
The hidden cost of PV cells is enormous. To make silicon polycrystalline or especially monocrystalline cells requires the same infrastructure as making silicon chips up to a point. Just the machines to pull the silicon ingots are incredibly expensive. I don't know what a solar cell fabrication foundry costs but a silicon chip fab can start at 1/2 billion to over a billion dollars. The processes used are also extremely energy intensive as the first steps are purifying and melting the silicon, a process similar to making glass except it is done in very small batches compared to glass making. Subsequent steps also involve baking at high temperatures to infuse dopant elements into the silicon. The only cheap part of the process is the raw material, sand.

going back to what J Tiers posted, there are a lot of assumptions in the "hidden costs". for one thing, growing Si for solar cells isn't the same thing as growing it for 12" Si wafers used to manufacture 45nm technology ICs. second, i worked for a company that owned the entire integrated circuit process (Si refining through ingot growing through wafer fab through device packaging and final test and shipment), and when they sold everything, it went CHEAP (to the Chinese). i'm sure that "recycled" equipment would have no problem turning out PV-cell-grade Si ingots. the equipment was no longer suitable for any IC technology below 0.25um without considerable investment.

i have no idea how much energy is used to make a PV cell though, so i don't know how long it takes to recoup that expense.

andy b.

Evan
07-25-2008, 02:32 PM
for one thing, growing Si for solar cells isn't the same thing as growing it for 12" Si wafers used to manufacture 45nm technology ICs

It is if you are making monocrystalline cells. The requirements for purity etc are exactly the same to grow a large single crystal of silicon. It's what you do with it after you make it where the processes differ.

jesse557
07-25-2008, 03:36 PM
Hi Evan,

I agree with most of your post, but single crystal Cz - pulled Si for solar is quite different than what your need for microelectronics. The purity requirements are not nearly as stringent for solar as they are for microelectronics. Cz Si for solar pv is pulled quicker and typically has a higher amount of impurities than microelectronics grade material. I know this is an aside from the original topic.

For what its worth, "energy" payback time for an installed grid tied solar pv system goes from 10 months to over 3 years depending on location and type of cell. The "monetary" payback time without subsidies is approximately never.

Jesse

J Tiers
07-25-2008, 08:06 PM
It is if you are making monocrystalline cells. The requirements for purity etc are exactly the same to grow a large single crystal of silicon. It's what you do with it after you make it where the processes differ.

Which is to a large extent last century technology anyway.......

Mono crystalline cells are a tad more efficient, but quite a bit more expensive than any other type.

The action is in amorphous and various thin film cells. Trying to stack the deck by quoting last century costs and impacts is just fraudulent.

You decide how you want the argument to come out, then add costs and make assumptions until it comes out how you decided you wanted it.... THAT is "new science" at work.

Makes the Salem witch trials seem remarkably intelligent and open-minded......:rolleyes:

wierdscience
07-25-2008, 08:28 PM
I looked into building a small backup system just to run a few lights and maybe a fridge in the event of another 2 -3 week long hurricane outage.

I wasn't practical,even as a backup.

If all the system cost me was $12,000 it still wouldn't be practical.Last years and the preceding 10 years my total bill was less than $1200 for the whole year.I did zero maintenance on anything and only had a couple nuisance outages besides the storm.

But as mentioned the real total cost of the system was more than $12,000,closer to $40,000.No way would I invest $40k in a system since 33 years would be the break even,maybe more or less.

My question is where does the subsidy for solar come from?Taxpayers?Industry?MUCH higher rates down the road?

Evan
07-25-2008, 08:39 PM
You off your meds Jerry? I didn't make any specific claims about what can pay back when or how much. I was just pointing out that you can't grow single crystal silicon if there is a lot of junk in the silicon. It has to be pretty close to semiconductor grade or it won't form a single crystal.

Single crystal cells are used when weight and/or space counts. Amorphous are much less efficient and need at least twice the area to produce the same output. They also degrade faster in the sun. Their output also drops faster when they get hot. Using an end of life assessment they probably generate about twice as much waste when they have to be replaced.



Amorphous silicon is the most well developed of the thin film technologies. In its simplest form, the cell structure has a single sequence of p-i-n layers. Such cells suffer from significant degradation in their power output (in the range 15-35%) when exposed to the sun.

The mechanism of degradation is called the Staebler-Wronski Effect, after its discoverers. Better stability requires the use of a thinner layers in order to increase the electric field strength across the material. However, this reduces light absorption and hence cell efficiency.

This has led the industry to develop tandem and even triple layer devices that contain p-i-n cells stacked one on top of the other. In the cell at the base of the structure, the a-Si is sometimes alloyed with germanium to reduce its band gap and further improve light absorption. All this added complexity has a downside though; the processes are more complex and process yields are likely to be lower.

http://www.solarbuzz.com/technologies.htm



Polycrystalline are generally the best bang for the buck still.

J Tiers
07-25-2008, 08:50 PM
You off your meds Jerry?

Eh.......... Not all of that was referring to you.

The "you" is the "generic form" referring to the person making the argument. Since that isn't you, don't worry.;)

it's friday... the only meds would be beer, and I don't want any right now.

BTW, the thin film cells are a LOT different from your grandpa's thin film and amorphous PV's.

I keep seeing/hearing the lifetime of cells of any and all types stated flatly......... and then I see mine, that were older than that, and were still going strong when the tree squashed them.

I'd like more just like them, same age. they put out more than the "new efficient" cells in average conditions here.

Less efficient, took about 2.5x the area for the old monocrystalline cells to produce what the modern polycrystalline does. But the old ones with that more area put out MORE when the sun was partly obscured by haze etc.

Just like those "stronger than steel" plastics..... there is always a BIG downside.

Evan
07-25-2008, 10:27 PM
Jerry,

You keep mentioning how long your panels lasted before they got squashed. How long they last is entirely dependent on how many hours of sunlight (and the flux level) they have received. If you have less sunlight than average your panels will last more years. Panels here will last much longer than even our 2013 hours of sunlight per year would indicate. A good deal of that sunlight is received in very cold temperatures and the panels will remain cold. It's primarily the heat that degrades the cells.

pcarpenter
07-25-2008, 10:34 PM
The thing I don't get is the original thinking about mideast oil etc. Who burns mideast oil to make electricity?

Its about like Pickens' "plan" with lots of pictures of big windmills. That would all work great if we had electric cars. We don't. Electric cars were first introduced back just after the high-wheel days. If making a suitable electric car was a great idea and easily accomplishable, I tend to think we would already have one. This, of course, is barring some magical discovery like superconductivity, that may all make it possible.

The problem here is that the demand may lead the technology...which is not all that uncommon. However, when that's the case, people are usually patient and willing to wait for a product that works well...and to pay for it. Instead, we have people who want to refuse to deal with the fact that we all own cars that may be around for a decade or more that still burn fossil fuels. We are not truly ready for a society with nothing but electric cars. What do you do about trucking or railroads...you are not going to run them on rechargable batteries. I know my wife and I just bought a vehicle and still have three years to pay on it. I am sure at the end of that three years, we won't be in any position to throw it away because it has no value in a country where you can't get fuel for it. We have oil and we *must* "drill our way out of it"...at least in the short term....but I digress.

I hope your Dad does not get cought in a scam pushed by electric companies to help them out of a stupid law.

Paul

JRouche
07-25-2008, 10:43 PM
Attractive rebates for sure, Id say down right irresistible. I like those discounts. Can you give some links to system he is looking at? If I could get a 40k setup for 12k I might jump on that myself.

I did the simple math and with my 100-120 monthly bill and Im looking at ten years then semi free electricity. My main panel is a 200amp/220vac. So about 44kw. I know I dont use it all at once but I would like to have at least 20-25kw available.

Does his system include everything, like the battery bank and inverter and safety disconect from the grid?

I really am interested now seeing the discounts involved. If the system was originally 40k then its prolly a really nice one..

Any info would be very much appreciated, you've seriously sparked my interest. Thanks, JR




The 12k price was after some pretty attractive rebates. I think the actual cost is around 40K.

Still, give it 5 more years and the actual cost is 12K and electricity has tripled...

It's kinda cool because my dad is no tree hugger and yet it just made financial sense.

Don't know the type of cell, I'll ask next time I'm down there.

J Tiers
07-25-2008, 11:22 PM
Jerry,

You keep mentioning how long your panels lasted before they got squashed. How long they last is entirely dependent on how many hours of sunlight (and the flux level) they have received. If you have less sunlight than average your panels will last more years.

I also have mentioned the panels PREVIOUS use..... the Carrizo solar power plant.

I would suppose the serious frying they got there would offset any lesser amount of sunlight at my location. They were a deep brown when I got them. Nothing anyone else can brag of is likely to be more exposure than at Carrizo.

Missouri has very hot, sunny, summers, but of course less total sunlight than at Carrizo. A similar set to mine is still functioning perfectly at my friend's in Black, MO.

Extract of Carrizo plant blurb from the website of "Center for land use ineterpretation"...

"The plant was originally constructed by the Atlantic Richfield oil company (ARCO) in 1983. ................................ The Carrizo Solar Company dismantled its 177-acre facility in the late 1990s, and the used panels are still being resold throughout the world."

The "late 1990s is not entirely true, mine were surplused out a little earlier, we got them around 1994. That makes them 25 years old now.

Mad Scientist
07-25-2008, 11:33 PM
Here is a company that is that using a different process to make photocells.

http://www.popsci.com/popsci/flat/bown/2007/green/item_59.html


The company produces its PowerSheet solar cells with printing-press-style machines that set down a layer of solar-absorbing nano-ink onto metal sheets as thin as aluminum foil, so the panels can be made for about a tenth of what current panels cost and at a rate of several hundred feet per minute. With backing from Google’s founders and $20 million from the U.S. Department of Energy, Nanosolar’s first commercial cells rolled off the presses this year.

Evan
07-26-2008, 02:36 AM
We'll see. I haven't seen any 90% off sales yet.

Then there is the small problem of global warming. Solar panels are made to absorb as much solar energy as possible. Unfortunately, they do a pretty good job of that but not of converting it to usable energy. If the panel is 10% efficient then you need to cover 10 times the area that 100% efficiency would need.

I calculated that replacing my dark red roof this year with an almost white (light grey) roof reflected back into space enough energy each year to entirely nullify the global warming contribution that could be derived from my use of grid power. If I had instead covered my roof with solar panels the effect would have been the opposite. It would approximately double the heat retained on my roof's share of the solar insolation and be the equivalent of doubling my power consumption in terms of my contribution to GW.

Paving the roofs of the planet with nearly black solar cells will greatly increase the heat retained. In global warming terms in operation they are worse than coal if you take into account the reduction in albedo they produce.

Solar power that increases the absorption of heat by the planet is most decidedly NOT "green". This is especially so because solar cells are perhaps the worst way to produce power based on total global warming positive coefficients.

Evan
07-26-2008, 03:00 AM
From the supplied link:


Cost has always been one of solar’s biggest problems. Traditional solar cells require silicon, and silicon is an expensive commodity (exacerbated currently by a global silicon shortage)

This is the reason that I totally stopped buying and reading Pop Sci years ago. Their reporting is riddled with misstatements and outright errors of fact. "Global Silicon Shortage" !!! Damn, did you hear that Mabel? We're running out of silicon!

"silicon is an expensive commodity". No it isn't, it's (ahem) dirt cheap. Processing silicon into usable form is expensive.

Your Old Dog
07-26-2008, 08:33 AM
WTF! Not only is the planet suffering from globular warming but it's running out of sand too? :D What are they using to walk on in the Middle East now?

J Tiers
07-26-2008, 09:21 AM
I calculated that replacing my dark red roof this year with an almost white (light grey) roof reflected back into space enough energy each year to entirely nullify the global warming contribution that could be derived from my use of grid power. If I had instead covered my roof with solar panels the effect would have been the opposite. It would approximately double the heat retained on my roof's share of the solar insolation and be the equivalent of doubling my power consumption in terms of my contribution to GW.


1)
The difference in REAL absorption may be less than you think. Even a chrome-plated metal sheet will get rather hot in the sun. (Not a quantitative statement, I know).

A granule-coated roof reflects in many directions, and the granules actual percent reflection at various wavelengths is probably not as good as the apparent light color would have you believe. After a couple reflections, net absorption is obviously higher.

You said "almost white" (light grey) roof. There is a lot of slop in that for absorption and heating....... although a light color roof "probably" is a few percent better than a dark one.

The effect is probably considerably less than you think it is. And STILL less after some granules have fallen off, as they naturally do.

Do you have a manufacturer spec for the average percent absorption vs wavelength of the shingles you applied? Do you have such a curve for "a solar panel" (whatever that is)?

If not, then you are indulging in "guesscience" by asserting that your roof is offsetting "X" amount of fossil fuel, or even that it has an advantage over a solar panel.

2)
And I think you have forgotten one very essential piece of information...

ALL THE SOLAR POWER CAPTURED BY A PV PANEL ENDS UP AS HEAT.

it may take a while, but eventually it is all heat.

THEREFORE ALL SOLAR POWER SOURCES ARE <most decidedly NOT "green"> as you put it.


3)
Mind, I consider that statement about "green-ness" BS anyway.

if the problem is "global warming", and it is caused by emissions of "greenhouse gases", then emitting LESS or NONE of them is "green".

Now, people can burble away spouting about the total energy required to get PV panels on a roof. How "scientific".

NOW, lets get down to business........ the grid infrastructure requires a huge investment of energy to build it, and then to maintain it, and of course to feed in coal etc to generate the power AFTER that huge energy investment is made.

It is a fact that the grid has yet to produce more power than it has taken so far to build and run it. So far the electric grid has been a net loss of power.

And the electric grid isn't even that efficient. The heat utilization starts out around 45-50%. Then there are transmission losses, and extra losses due to poor power factor, etc. The net efficiency may be below 40% at the user.

DO you REALLY suppose that PV panels are such a total disaster when they are now approaching 20%+ efficiency in the best types?

Evan
07-26-2008, 09:35 AM
Jerry,

I have quantitative evidence that it reflects as I say it does.

http://vts.bc.ca/pics4/roofcolor.jpg

That also doesn't take into account the lunar backscatter effect that works to more than double the reflection in the direction of the source. It applies to granular materials in general and works much the same as a retroreflector.


And I think you have forgotten one very essential piece of information...

ALL THE SOLAR POWER CAPTURED BY A PV PANEL ENDS UP AS HEAT.


I haven't forgotten anything. The point is that with only 10% average efficiency in the real world you have to capture 10 kilowatts of energy to produce 1 kilowatt of power. Since the average albedo of the planet is around 20 to 30% and the albedo of the solar panels is maybe 5% you are capturing an EXTRA couple of kilowatts for every 1 kilowatt you can use. That's a couple of KW above and beyond what would normally stay here on earth.

As for the reflectance of solar cells, every effort is made to minimize that. If you look at the photo of the new Nanosolar cells they appear black. Appearing black is a very good clue that they are in fact black.

hitnmiss
07-26-2008, 09:49 AM
Attractive rebates for sure, Id say down right irresistible. I like those discounts. Can you give some links to system he is looking at? If I could get a 40k setup for 12k I might jump on that myself.

I did the simple math and with my 100-120 monthly bill and Im looking at ten years then semi free electricity. My main panel is a 200amp/220vac. So about 44kw. I know I dont use it all at once but I would like to have at least 20-25kw available.

Does his system include everything, like the battery bank and inverter and safety disconect from the grid?

I really am interested now seeing the discounts involved. If the system was originally 40k then its prolly a really nice one..

Any info would be very much appreciated, you've seriously sparked my interest. Thanks, JR


Not sure on the system and rebate specifics... I'll take some notes next time I'm down as I'm interested too.

No batteries. Excess is pushed into the grid, literally spinning the meter backwards.

Evan, I consider myself pretty open minded and I also consider you to be very intellegent. That said your arguments of more energy used to make the cells than they produce and that they will add to the global heat load seem to be extreme. I'm no debater so you'll probably kill me arguing but I'm really after your points of view here. That said, from my thermodynamics course EVERYTHING increases entropy, sounds like your solar cell arguments are merely repeating that law?

If solar cells are a bad idea I'd like to really know that.

Evan
07-26-2008, 11:28 AM
The point I am making is one that has been completely ignored in the press and even in most scientific analysis. Global warming is a matter of balance. The amount of solar radiation that that the earth captures must be balanced by the amount of heat that escapes. Even a tiny change will upset that equilibrium over time until a new equilibrium is reached.

What that means is that anything we do that causes more of the sun's energy to be retained as heat here on Earth is a contributor to global warming. The amount of energy that land on the surface from the sun is around 1 kilowatt per sq meter on a good sunny day. A percentage of that energy is reflected right back into space as visible light and so does not contribute to heating the planet. That percentage is quantified as the "albedo" which is the average reflectivity of a surface. The average albedo of the land area of the Earth is around 30% meaning that of that 1000 watts of energy that reaches the ground about 30% is reflected back out.

The albedo is measured in exactly the same way as my photograph of my roof. Pure white is an albedo of 100 and absolute black is zero.

If we alter the terrain so that it absorbs more of the sun's energy that falls on the surface it alters the radiation balance just the same as when a green house gas is released into the atmosphere. That is because absorbed visible light is converted to longwave heat radiation which is then absorbed by the greenhouse gasses in the air, including water vapor. By increasing heat capture at the surface we make a direct single stage contribution to the amount of heat trapped by the Earth. There is no compensating mechanism to counteract that either.

My red roof absorbed about half of the energy that fell on it. If we entirely discount the infrared that leaves about 500 watts per sq meter so it was absorbing about 250 watts per sq meter and converting that to heat. When I replaced it with a light grey roof the reflectance increased to around 80%, a 30 percent difference. That means my new roof is absorbing only about 100 watts per sq meter compared to 250 watts for the old roof.

The area of my roof exposed to the sun on average is about half the total roof area, or about 80 sq meters to be conservative. The average hours of sunlight here in Williams Lake as measured by sunlight strong enough to burn a piece of cardboard with a magnifier is 2013 hours per year (http://data.piercecollege.edu/weather/duration_sunlight_recorder.html).

250 watts per sq meter x 80 x 2000 = 40 megawatts of solar energy per year that was absorbed by my roof and retained as heat. My new roof only absorbs 16 megawatts per year, a difference of 24 megawatt hours. I use about 2 megawatt hours of electrical energy per month so replacing my roof with a lighter color roof has effectively reduced my heat contribution in the same proportion as our electricity consumption yearly. It effectively compensates 100% in terms of global warming effect for the grid power we use.

If, however, I had replaced the roof with 80 sq meters of solar panels with a reflectivity of 5% in order to produce about 6 kilowatts of power on an average sunny day and not counting any of the other energy intensive aspects of a solar electric installation the solar cells alone would increase the absorption to about 475 watts per sq meter. That would total 475 x 80 x 2000 = 76 megawatts of retained solar energy per year in order to to produce the same amount of power that I buy from the grid. That would be double my grid use over and above the power I actually consume.

So, for every watt of solar cell power I capture I also capture 2 watts of heat that wouldn't be captured if I didn't use solar cells. Multiply that times hundreds of millions of potential solar installations and we have a problem.

It's also an indisputable and easily measured problem. It isn't open to varying interpretations like the subject of greenhouse gasses is. Captured solar energy is easy to measure and quantify as is the reflectance of objects on the ground. There isn't any possibility of disputing the effect of covering the surface with dark colored heat absorbing materials. It will warm things up.

J Tiers
07-26-2008, 12:08 PM
Jerry,


I haven't forgotten anything. The point is that with only 10% average efficiency in the real world you have to capture 10 kilowatts of energy to produce 1 kilowatt of power. Since the average albedo of the planet is around 20 to 30% and the albedo of the solar panels is maybe 5% you are capturing an EXTRA couple of kilowatts for every 1 kilowatt you can use. That's a couple of KW above and beyond what would normally stay here on earth.

As for the reflectance of solar cells, every effort is made to minimize that. If you look at the photo of the new Nanosolar cells they appear black. Appearing black is a very good clue that they are in fact black.

You are making an assumption about the average reflectance of the earth..... if you live in a woodland, you are surrounded by large plants that reflect relatively little of the energy that falls on them. They have to evaporate water to reduce their temperature, which obviously simply moves that heat around.

Bare earth reflects a variable amount, but the good stuff up where you are reflects less than elsewhere. In the North, glacier areas, soil generally is rather black in appearance, which is a good clue that it IS black and reflects little. It is usually covered by plants, which themselves use solar power, and reject heat, for a slight gain.

So I assert that you are possibly reducing the absorption EITHER WAY with the roofs, versus bare soil, and quite possibly vs plant-covered areas.

Solar cells probably get back into the area of "normal" absorption, AND they produce power....... net gain / benefit, small downside on the reflectivity issue, for your area. Naturally, for your area, winter input is so much less that the reflectivity isn't as important.


That would total 475 x 80 x 2000 = 76 megawatts of retained solar energy per year in order to to produce the same amount of power that I buy from the grid. That would be double my grid use over and above the power I actually consume.

And so solar might well be either a wash, OR a very slight advantage over grid power, since 2 units or more of power must be "released" (as fire or equivalent) in order to get each 1 unit of power to you. Your hydro power is admittedly different, but applies to very little of the total power world-wide, so I discount it generally (your specific and individual case notwithstanding).

And that is AFTER
* the entire huge energy investment in the grid to begin with

*into which we MUST add the environmental damage incidental to power lines

*to say nothing of direct and continuous greenhouse gas emissions for non-hydro generation

*AND the huge energy use to construct any hydro power plants.

*plus the maintenance costs energy-wise for mechanical equipment and the grid infrastructure, even for hydro

Solar has an up-front cost, but a much lower ongoing maintenance cost.

Sorry, Evan, your argument against solar power is not getting very far up to now.....

rotate
07-26-2008, 12:35 PM
From the supplied link:

This is the reason that I totally stopped buying and reading Pop Sci years ago. Their reporting is riddled with misstatements and outright errors of fact. "Global Silicon Shortage" !!! Damn, did you hear that Mabel? We're running out of silicon!

"silicon is an expensive commodity". No it isn't, it's (ahem) dirt cheap. Processing silicon into usable form is expensive.


If you consider who the target audience is for Pop Sci magazine, then this should not be a surprise. I have fun reading it when I'm at my barber, but it annoys me to no end when people talk about an article that they read in that magazine and say "did you know that...". :rolleyes:

Half the stuff that report on is either a vapourware or cleverly disguised ad. General public just isn't interested in real science. :(

Dragons_fire
07-26-2008, 02:07 PM
the real story is that the government found aliens on MArs, and global warming is just a coverup so we dont freak out!!! haha

Evan
07-26-2008, 06:07 PM
You are making an assumption about the average reflectance of the earth....

No I am not. Look it up. It's a well quantified value. It makes not a whit of difference what the albedo of my surroundings is, that doesn't affect how much excess heat covering my roof with solar cells would capture.


So I assert that you are possibly reducing the absorption EITHER WAY with the roofs, versus bare soil, and quite possibly vs plant-covered areas.


This is a global issue, not a house by house micro heat island issue. What I do affects the entire planet in a tiny way. Increasing the absorption of heat isn't desirable if the planet is warming, no matter what I am surrounded with. What a billion people do is a big deal.

If you want to crunch some real numbers try calculating how much extra heat would be retained by a solar collector system that has an albedo of 5% and is big enough to supply the entire USA. Another thing to consider is that warming from this cause is independent of any issues about greenhouse gasses and who or what may be responsible for them. Even if there were no greenhouse gas problem decreasing the average albedo of the planet will cause it to become warmer. Period. The logic is irrefutable.

J Tiers
07-26-2008, 09:04 PM
No I am not. Look it up. It's a well quantified value. It makes not a whit of difference what the albedo of my surroundings is, that doesn't affect how much excess heat covering my roof with solar cells would capture.

This is a global issue, not a house by house micro heat island issue. What I do affects the entire planet in a tiny way. Increasing the absorption of heat isn't desirable if the planet is warming, no matter what I am surrounded with. What a billion people do is a big deal.


there are not a billion of you , in your particular place.

Your assertions were with respect to YOUR individual and specific impact..... not the other billions, many of whom do not own what you own, nor live where you live and have far less impact.

Therefore YOUR impact due to YOUR choices, vs alternatives, or YOUR property area covered by woodlands instead of cleared for your house etc, is VERY MUCH the point.

YOUR exact area is not "average", it is how YOU impact YOUR area vs leaving it "natural"...... or putting on panels.

Many conifer woodlands are a very dark color overall from the air. Very nearly the same as black. And they are that way all year, unless covered by snow. Northern soils are often very black also.

The difference in albedo between that and your (hypothetical?) black solar cells is presumably small. My solar panels (new) are actually an intense medium-light blue, but if you say there are black ones up there, I'll believe you.

Rich Carlstedt
07-26-2008, 10:47 PM
Well I agree with Evan...he has made some great points
Let me offer several other points.

We know that cities have warmer air because of pavement. It is primarily black. Evans point about roofs is correct.
Engineers know that Black versus white objects have a 4 fold difference in heat dissipation

The true cost of silicon is in the cost of the panels. HOWEVER, because of a non-representative government, other folks , like ME, pay for you to have a solar panel on your roof.
If no tax credits, or incentives were offered, and I could keep my own money, instead of giving it to you, I doubt anyone would run off and buy a solar panel and pay its real cost

So I state.
I have never heard of anyone getting into TOTAL solar power support for their home, without some form of tax or money rebate.
That 'fact" makes all "cost" discussions subject to real world analysis, not hypothetical assumptions.

In simple terms, would you brag about your "achievement" in gas mileage , if someone else was filling your tank ?
Rich

Evan
07-26-2008, 10:58 PM
there are not a billion of you , in your particular place.

Your assertions were with respect to YOUR individual and specific impact..... not the other billions, many of whom do not own what you own, nor live where you live and have far less impact.

Jerry,

You aren't getting it. My circumstances have nothing to do with it. It's dead simple. If we start throwing up sq kilometers of black solar cells it's a sure thing they won't be replacing or covering something else that was black in most cases. Even things that we characterize as "black" usually aren't such as road asphalt. Solar cells are made to resemble a black body as much as possible. That is how the efficiency is maximized. Any energy they reflect is energy they can't use. Although most solar cells don't look black they they have very low reflectivity, just not even across the spectrum. Solar cells get HOT in the sun. It's the same as putting a black roof on your house.

Evan
07-26-2008, 11:09 PM
The difference in albedo between that and your (hypothetical?) black solar cells is presumably small. My solar panels (new) are actually an intense medium-light blue, but if you say there are black ones up there, I'll believe you.

They aren't hypothetical and they aren't mine. They are black though.

http://vts.bc.ca/pics4/nanosolar.jpg

J Tiers
07-27-2008, 12:06 AM
We know that cities have warmer air because of pavement. It is primarily black.

Not so fast.....

Concrete is not black. Huge amounts of concrete is put down around here as pavement........ more than asphalt, it seems. Most parking lots are either light-colored gravel, or concrete.

Asphalt is black when first put down. After a while it turns whiteish-gray, as the top layer of tar wears off and the aggregate starts to show through. The older it is the whiter it is.......

I won't claim that the reflectivity of cities is less than other areas, but it is perfectly possible.

The "heat island" is as much about other factors as it is about asphalt... be careful to not make generalizations that may not apply.

1) open land, even if grassy, is much hotter than woodland in the day. Cool breezes blow out of woodlands (there is a reason), Cities are often like open land, although where I live it strongly resembles woodland with houses in it, since it is densely tree-covered. Trees even substantially shader the roadways.

2) woodland "moves heat" away, as the trees evaporate water to stay cool, and thus move the latent heat of vaporization elsewhere as the wind blows. THEY DO NOT HOLD HEAT

3) Cities are largely composed of rock-like materials that EVEN IF WHITE, absorb and hold heat just like open rocky landscape. They may resemble a western desert in albedo and a rocky desert area in heat retention.



They aren't hypothetical and they aren't mine.

Any collected solar heat is heat gain. The sun shines on the earth, sorry, that's a fact.

heat gain that is re-radiated is no problem. Without the various excess heat-retaining gases, gained heat would be re-radiated much more easily, and the heat balance would be hardly affected.

I doubt that solar cells sufficient to affect the net heat input can be made any time soon. The supposedly black roads that were just brought up don't cover enough area to make the picture from space particularly different. I have no idea what the total black paved area is, but I suspect it is small compared to total exposed area. Add roofs and it is still small. And it is densest primarily in Europe, with a large but less dense amount here in the US. Canada can forget about it, there isn't much paved up there......

However, it makes little sense for solar cells to collect energy they cannot use. That sounds much more like a poor implementation than a desirable feature.

Now, look at this rationally..........

Choice 1: burn MORE stuff that INCREASES the WORLD-WIDE RETENTION of heat energy from solar input, PLUS directly inputs net heat equal to at least twice the power generated.

Choice 2: replace some of that gas-generating power production with direct conversion of solar energy to power, EVEN if it slightly increases the overall solar "gain".

So you BOTH want to keep making the problem of retained heat of all sorts, worldwide, worse, because one possible partial solution may have a minor local impact on net solar gain?

That sounds non-rational........


As far as the subsidy aspects........ You really have NO IDEA how that subsidy thing is supposed to work, do you?

The government is using some of your tax dollars to encourage a behavior that is expected to benefit the entire society, including you.

perhaps you would like to opt-out of taxes for police and fire departments as well?

Do you want a rebate if you never need the fire department?

Being a part of society involves participation in funding some things which may never benefit you directly, BECAUSE THEY WILL BENEFIT OTHERS IN SOCIETY, OR BECAUSE THEY MAY BENEFIT YOU, BUT NOT RIGHT AWAY, so you might die first.

"Government" may naturally be ill-informed, may be indulging in abusive behaviour, etc. The voting process is supposed to allow removing 'governments" which do NOT do as they should.

You can of course vote against them, in which case we will find out if the majority supports them. it is possible that a small group is pushing a bad program and need to be stopped. Or that a majority of uninformed citizens can be convinced by a small special-interest group to vote against their own best interests.

But if you just want to pick and choose your funding of society-wide benefits based on your own narrow desires and possibly bigoted opinions, you really should move out altogether and find a different country to live in. That isn't how it works here. And it should not be.

Evan
07-27-2008, 02:00 AM
Any collected solar heat is heat gain. The sun shines on the earth, sorry, that's a fact.

heat gain that is re-radiated is no problem. Without the various excess heat-retaining gases, gained heat would be re-radiated much more easily, and the heat balance would be hardly affected.


Now you are making hand waving statements. You have no idea how much impact it would have on the entire environment. The problem is that on a per kilowatt basis solar in effect "generates" much more waste heat than other energy sources. Not only are solar cells very energy intensive to make, possibly to the point that they never pay back that energy debt, the energy debt is further increased for every kilowatt of power they collect because they also collect 7 to 9 more kilowatts of heat.

About one third to one quarter of those kilowatts of heat would NOT be collected if the solar cells were not there, in most cases. The visible radiant energy would be reflected back into space instead of being converted to long wave radiant energy that is blocked by the atmosphere. There is even a multiplier factor. Since it is obviously clear sky when the sun is shining the reflected light, however much it is, is always able carry away the energy to space in just milliseconds. However, if instead it is collected as heat it isn't all immediately reradiated and as it is it may no longer be clear sky. This will enhance the heat collection effect and there isn't a counterbalancing set of circumstances. It will always be cloudy some of the time after the heat has been retained while it will always be clear if the sunshine is immediately reflected.


1) open land, even if grassy, is much hotter than woodland in the day. Cool breezes blow out of woodlands (there is a reason), Cities are often like open land, although where I live it strongly resembles woodland with houses in it, since it is densely tree-covered. Trees even substantially shader the roadways.

2) woodland "moves heat" away, as the trees evaporate water to stay cool, and thus move the latent heat of vaporization elsewhere as the wind blows. THEY DO NOT HOLD HEAT

3) Cities are largely composed of rock-like materials that EVEN IF WHITE, absorb and hold heat just like open rocky landscape. They may resemble a western desert in albedo and a rocky desert area in heat retention.

So what? That has nothing to do with the reflectivity or lack of it of solar cells. The average albedo of the landscape is 30%. That is an established scientific fact and includes all the variations from dark to light areas. Adding solar cells to the landscape will reduce the albedo and increase the heat retained.

This is the key fact that is being widely ignored. The assumption is that the sun is shining on us anyway so we may as well use it. The reality is that if we use it by capturing most of the heat energy it contains we increase global warming. If we want solar cells to be heat gain neutral in use then they must reflect on average at least 30% of the insolation. That would mean a severe reduction in efficiency which would require yet more panels be made so even that isn't a solution.

andy_b
07-27-2008, 09:56 AM
i just wanted to toss something out there regarding the "global silicon shortage". again, due to some insight i have into the semiconductor industry, there are most definitely periods of "global silicon shortages". these aren't sand shortages, they are processed silicon ingot and wafer shortages (a few years ago there was a HUGE one). if you just poured sand into a mold to make solar cells, i'm sure these shortages would not affect price, but since you need processed silicon, it definitely comes into play.

andy b.

Mad Scientist
07-27-2008, 10:02 AM
If we are really going to worry about all this “wasted” heat then what we need to do is collect it, along with the electricity, and then use it in some useful manner that will eliminate the need to use some other form of manmade heat.

J Tiers
07-27-2008, 10:42 AM
If we are really going to worry about all this “wasted” heat then what we need to do is collect it, along with the electricity, and then use it in some useful manner that will eliminate the need to use some other form of manmade heat.

You have seen the issue that Evan prefers to ignore.

The alternatives (basically coal burning) we have at present INCREASE THE RETENTION OF HEAT, AND WILL CONTINUE TO INCREASE IT, SPIRALING UPWARDS IN RETENTION AS LONG AS WE CONTINUE TO USE THEM.

The PV alternative is ONE (among others) which offsets not only the direct heating (2x power generated, net) caused by burning coal, BUT ALSO THE LINGERING EFFECTS OF THAT COAL BURNING ON THE RETENTION OF SOLAR GAIN FROM ALL OTHER "CAUSES", BE THEY EVAN'S "BLACK" SOLAR CELLS OR BLACK ROCKS, DIRT, TREES, OR THE OCEANS*.

it is important to remember that the coal alternative increases the retention of heat WORLDWIDE, heating due to land area, oceans, cities, or solar cells. it is not just "local" in effect.

Evan and others keep harping on the idea that solar cells (using monocrystalline silicon as the model cell, and only possible cell) "can never pay back their huge energy cost and the horrible chemicals used to diffuse the junction into the silicon"... He ignores the newer technologies which allow cells to be "printed" by the tens of square meters at a time, with less obnoxious chemicals and much less energy input.

They also ignore the fact that the existing electric power grid has yet to (and can never), generate enough power to make the materials used in IT.

"Hand waving" or not, a simple qualitative look suggests that there are three alternatives......aside from nuclear power, which has already been effectively taken off the table.

1) stop using power, and go back towards pre-industrial life, accepting the massive human die-off that results. This is the alternative that most traditional environmentalists prefer, whether they admit it or not.

2) keep burning coal (stored solar power), which will keep INCREASING the heat retention per watt of solar gain, and raise the earth's temperature. This seems to be Evan's "solution", even though he has already accepted and endorsed the fact that it does and will continue to cause heating, at a steadily increasing rate.

3) use alternative means of converting solar power (in it's various forms) to usable power, even if SOME of them DO cause a minute increase in the global average heat input. Keep working on increasing the efficiency of these means so that the effect is minimized**. Add some other means such as geothermal etc, if and as they become more widely usable.

it seems obvious that alternative "2" is not a "solution" which will solve anything, regardless of Evan's roof. I can't imagine ANYONE who can think supposing it is worth considering, unless they deny the effect altogether.

Alternative "1" will work fine, but may not be very acceptable, since once the environmentalists have all shot themselves to save the planet, the rest will keep right on going as they are until they do it to themselves with a big mess.

* The oceans, by far the dominant feature of the earth's surface, are about the same blue color from space as the usual silicon solar cell.

One might, with Evan's logic, suppose they reflect about the same amount of energy...... so much for the heating. If we covered the earth 100% with that color, we would logically not equal what the oceans now already absorb, as they have more surface area than the land.

** One would accurately presume that ideal solar cells , which are what is being worked on, would be efficient. Clearly, the more efficient the cell, the fewer are needed, and the smaller the amount of area covered by them. Doubling the efficiency halves the area used........ Obviously that is of benefit, even if only on an economic basis.

Evan
07-27-2008, 12:18 PM
You have seen the issue that Evan prefers to ignore.

The alternatives (basically coal burning) we have at present INCREASE THE RETENTION OF HEAT, AND WILL CONTINUE TO INCREASE IT, SPIRALING UPWARDS IN RETENTION AS LONG AS WE CONTINUE TO USE THEM.
And solar cells capture excess heat as long as they are in use. The problem is they CAPTURE HEAT THAT WOULDN'T BE CAPTURED OTHERWISE.

The PV alternative is ONE (among others) which offsets not only the direct heating (2x power generated, net) caused by burning coal, BUT ALSO THE LINGERING EFFECTS OF THAT COAL BURNING ON THE RETENTION OF SOLAR GAIN FROM ALL OTHER "CAUSES", BE THEY EVAN'S "BLACK" SOLAR CELLS OR BLACK ROCKS, DIRT, TREES, OR THE OCEANS*.

They are not MY solar cells Jerry, they are the latest and "greatest" idea in solar technology. It also doesn't matter which apparent color they are. The apparent color of a solar cell is narrow bandwidth reflection. All the other bands are absorbed. That is on purpose.

it is important to remember that the coal alternative increases the retention of heat WORLDWIDE, heating due to land area, oceans, cities, or solar cells. it is not just "local" in effect.

Same as with the heat retained with solar cells.

Evan and others keep harping on the idea that solar cells (using monocrystalline silicon as the model cell, and only possible cell) "can never pay back their huge energy cost and the horrible chemicals used to diffuse the junction into the silicon"... He ignores the newer technologies which allow cells to be "printed" by the tens of square meters at a time, with less obnoxious chemicals and much less energy input.

I'm not even talking about monocrystalline solar cells at all. I am specifically talking about those newer printed cells. That is what the picture I posted is about, the Nanosolar product.

They also ignore the fact that the existing electric power grid has yet to (and can never), generate enough power to make the materials used in IT.

I never mentioned any "horrible chemicals". The diffusion process is extremely energy intensive.

"Hand waving" or not, a simple qualitative look suggests that there are three alternatives......aside from nuclear power, which has already been effectively taken off the table.

More handwaving about handwaving?

1) stop using power, and go back towards pre-industrial life, accepting the massive human die-off that results. This is the alternative that most traditional environmentalists prefer, whether they admit it or not.

2) keep burning coal (stored solar power), which will keep INCREASING the heat retention per watt of solar gain, and raise the earth's temperature. This seems to be Evan's "solution", even though he has already accepted and endorsed the fact that it does and will continue to cause heating, at a steadily increasing rate.

Don't make assumptions. Coal is a very dirty way to make power. reducing consumption is much better and is also extremely doable. Putting a light colored roof on my house has cooled the interior considerably in the current hot weather. I don't have air conditioning and don't need it even when it is around 100f outside.

3) use alternative means of converting solar power (in it's various forms) to usable power, even if SOME of them DO cause a minute increase in the global average heat input. Keep working on increasing the efficiency of these means so that the effect is minimized**. Add some other means such as geothermal etc, if and as they become more widely usable.
[edit to correct math typo]
The estimated area required to supply the USA from solar power alone is 10,000 sq miles of solar cells. If they trap an excess of 2 kilowatts of heat per hour per sq meter over 3000 hrs per year of sunshine the numbers are staggering. 2,589,988 sq meters per sq mile x 3000 hrs per year x 2 kilowatts x 10,000 sq miles=155,399,280,000,000,000 excess watts per year trapped.
That's 155 PETAWATTS. It is also, not coincidentally, the same as TWO TIMES the current total energy consumption of the USA, the largest consumer on the earth. This is not "a minute increase in global output".


it seems obvious that alternative "2" is not a "solution" which will solve anything, regardless of Evan's roof. I can't imagine ANYONE who can think supposing it is worth considering, unless they deny the effect altogether.

Alternative "1" will work fine, but may not be very acceptable, since once the environmentalists have all shot themselves to save the planet, the rest will keep right on going as they are until they do it to themselves with a big mess.

* The oceans, by far the dominant feature of the earth's surface, are about the same blue color from space as the usual silicon solar cell.

One might, with Evan's logic, suppose they reflect about the same amount of energy...... so much for the heating. If we covered the earth 100% with that color, we would logically not equal what the oceans now already absorb, as they have more surface area than the land.

The oceans are excellent absorbers of heat. You are misleading yourself and others by thinking that the reflection of a single color of light equates to the reflection of a large amount of energy. It doesn't. Ever notice how an antireflection lens coating looks BLUE?

If we covered the land with something that absorbed the same as the oceans do we would have to use something like solar cells. Oops.

** One would accurately presume that ideal solar cells , which are what is being worked on, would be efficient. Clearly, the more efficient the cell, the fewer are needed, and the smaller the amount of area covered by them. Doubling the efficiency halves the area used........ Obviously that is of benefit, even if only on an economic basis.

But, we don't have ideal solar cells. Real world efficiency once they are enclosed in slightly dirty glass frames is maybe 10% at best.

Evan
07-27-2008, 12:21 PM
If we are really going to worry about all this “wasted” heat then what we need to do is collect it, along with the electricity, and then use it in some useful manner that will eliminate the need to use some other form of manmade heat.

That is a workable alternative in some cases but not many. There isn't much need for low grade heat on a sunny day in a southern climate where solar works best. It also isn't what the manufacturers of solar cells are making and selling. It also requires a major increase in the expense of building solar cell panels as they requires some form of circulating cooling system to carry away the excess heat and store it somehow.

J Tiers
07-27-2008, 12:52 PM
Evan, you are side-stepping and hitting on side points.....

You refuse to address the real point.

We are ALREADY releasing 2x the energy usage in the US..... and to DO that we are INCREASING THE HEAT RETENTION OVER THE ENTIRE EARTH.

CHINA is doing far worse than that....... they are burning coal that doesn't evn generate power...... in huge coal fires that they refuse to try to put out. Ones that dwarf the fires here.

If we simply continued to use the same energy as now, but REDUCED the heat retention potential, a simple application of logic indicates that the rate of heat increase HAS to slow, at the very minimum.

If we ALSO reduce consumption, obviously that is better.

I don't see a point in continuing this when you will NOT address the point.

See yah.

Rustybolt
07-27-2008, 02:41 PM
I read somewhere on the web recently that there is an attempt to make solar cells using nanotechnology and plastic film. thereby reducing the cost of a solar cell to less than a dollar a watt. Does that sound right? In any event the idea is to make it so cheap everone will have some application for it.For myself I'd like to see more nuclear power plants.

Evan
07-27-2008, 02:49 PM
You refuse to address the real point.


No, because my point has nothing to do with other energy sources. The real point is that solar cells are NOT a green alternative. They have an unrecognized and unpublicized serious global warming potential that is independent of the issue of greenhouse gasses and carbon emissions.
[added]
Furthermore, the global warming potential of solar cells is real, quantifiable, measurable and undeniable. Even if we didn't have any issues relating to CO2 etc solar cells would STILL be a global warming threat. Used in large quantities they will upset the heat gain/loss equilibrium of the Earth. It will be no different than simply painting 10's of thousands of square miles of the planet black in the sunniest areas you can find.

Rich Carlstedt
07-27-2008, 04:55 PM
J Tiers
"As far as the subsidy aspects........ You really have NO IDEA how that subsidy thing is supposed to work, do you?
The government is using some of your tax dollars to encourage a behavior that is expected to benefit the entire society, including you. "

So I have no idea ?
Are you kidding ?
I surely do, its called tax me for your theory , whether right or wrong.
Its called being stupid, when Nuclear Energy makes electricity for 2 cents a KWH and Solar cells can never come close. .....NEVER !
When people like you reffer to it as 'free energy" I realize how short sighted they are. There is no free lunch. I do not expect as a citizen to finance every cock and bull idea about "saving Energy" or perpetual motion.
Look at what the Ethanol program has done !
Any time Government has entered free market programs. disaster follows
True FREE Governmnent is for social interaction, and not control
Socialism is a form of Government that dictates policeys for the 'betterment of the people" but in who's eyes?
I pay my tax dollars to support freedom, not to benefit someones "dream'

If the dream is pure, it will stand on its on feet

You have much to learn my friend, about responsibility to others and how it differs from "obligation for financial aid"

Rich Carlstedt
07-27-2008, 05:05 PM
J Tiers

So why not paint everything White ?
All roads, all houses, all land should be whitewashed..
Problem solved..Lets put a tax on it, and let You pay for that hairbrained idea.

Wait, who said it was hairbrain.. I mean we could pass a law that all clothes would be white, and every paint maker would be compelled to only make white paint or be forced out of business. All cars would be white, and even rivers should be dyed that color
(AKA carbon footprint taxes....OOOPPS, I mean Carbon CREDITS...wow, I almost slipped)

Thats total non-sense right ?
I mean IT IS for the benefit of all ???
and I would let you pay for it , and if you complained, I could say you don't know what you are talking about !

Sounds good to me.

aboard_epsilon
07-27-2008, 05:51 PM
I've said this before ..
you have to tackle this problem at source

And that is :- people ...there are just too many of them !!!..
reduce population ...will reduce all your global warming ...quicker than any other method.

Instead of lecturing us about cfcs and carbon ...they should be encouraging us to have less children....

Can anyone give me an argument against these thoughts of mine ...other than that, the economies would slow down ,and the people in power don't want that ...cause they are all money making greedy bastards ...and are even making more out of this global warming crap........so....what are the implications of less population ..

Heck they could even reward people who don't have children ...that would still work out cheaper then trying to fight the results of over population with technology.



all the best.markj

pressurerelief
07-27-2008, 10:23 PM
IF it was me, I would take the $12K and invest it in the market with the help of my financial planner. I would take the earnings and reinvest for 5 years. Then I would pay for my electric with my earnings and buy toys and tools with the remaining return on investment. Seems like an upside as opposed to waiting 18 years to break even if it would ever happen.

Am I missing something?

My Green thinking usually involves a bank and early retirement.

P/R

J Tiers
07-27-2008, 10:35 PM
You have much to learn my friend, about responsibility to others and how it differs from "obligation for financial aid"

Not so. Read what I wrote....... before you run off on a rant. You are far too smart a person to really believe what you wrote, once you think about it.

The social contract of common government means we DO pay for things that we don't use, or never use. You are not, I hope, on Medicaid, but you are paying for it, because some of the society need it.

The other side of that is that if we, as a community, decide we ALL don't want to pay for that, we generally get that taken care of through the voting process.

But, those who lose out in the voting, and are on the dissenting side, don't have the option of saying "well, so what, I'm STILL not paying for that"..... That position is sociopathic, or at least indicative of the person actually not wanting to be a part of society. People like that are in it for what they can get, and are basically parasites and thieves. Acting on that motivation gets penalties applied.

if you don't like government, you have options. move to another country and join theirs...... I am far from agreeing with everything that goes on in the USA, but I recognize that belonging to the "common weal" has obligations and duties, including putting up with some things one does NOT agree with in any way.

I reserve the right to vote against the half-baked cretins who propose and put through the plans I don't like. And if enough like-minded people agree with me, something will be done about it.

Don't make the mistake of thinking that is some sort of socialistic double-talk. Not at all, I believe you will find it is very much in line with the ideas of the "founding fathers".

On the other hand, the idea of "if I don't like it it isn't the law for me" is totally out of step with the FF, and forms no part of the overall social contract which is the basis for tribal, town, and any higher form of government.

J Tiers
07-27-2008, 10:56 PM
J Tiers

So why not paint everything White ?
All roads, all houses, all land should be whitewashed..
Problem solved..Lets put a tax on it, and let You pay for that hairbrained idea.

Wait, who said it was hairbrain.. I mean we could pass a law that all clothes would be white, and every paint maker would be compelled to only make white paint or be forced out of business. All cars would be white, and even rivers should be dyed that color
(AKA carbon footprint taxes....OOOPPS, I mean Carbon CREDITS...wow, I almost slipped)

Thats total non-sense right ?
I mean IT IS for the benefit of all ???
and I would let you pay for it , and if you complained, I could say you don't know what you are talking about !

Sounds good to me.

I have no idea why that is directed at me...... I believe it should be addressed to Evan.

He is the one talking about total reflectivity, etc........

My whole point was that if you accept, AS HE DOES, the idea of global warming as a result of burning carbon etc, it makes NO SENSE to then turn around and ban one promising alternate source of energy because you think it may add some heat. Not IF the alternative is to keep pumping out exhaust that makes the problem exponentially worse, while the banned technology would be only linearly worse.

I realize that you don't accept 'global warming" at all.

That is probably because you don't see how the problem as presented could be fixed except by unbelievably severe actions now. Basically "freezing in the dark".

I agree. The solutions have not been thought out, assuming the whole thing is not a goof-up among the scientists.

I am also not 100% certain that it is 'evenly due" to all types of carbon burning..... I think some forms are likely to be disproportionately responsible for GW, and I think aircraft, for instance, are one major factor that is being ignored in the rush to blame the USA and personal cars*. Any relative scaling of severity is not being given any scientific study, since any such proposal is shouted down by a mob who prefer to blame US cars, and US cars alone.

However, the "APPROVED CURE" seems to be for all the "first world", and ESPECIALLY the USA, to retreat to pre-industrial grass huts, while the "third world" goes fully industrial and pollutes worse and worse, because they can and because they "have not had their turn yet".

That makes no sense to me either.

In the first place, it means the third world will damage their own future, instead of being a model for "sustainable growth" if there is any such thing.

it also can't be made to stick without "peasant revolts". if the problem is real, everyone is responsible, and the blame and punishment can't be stuck onto one group. The other societies which are not yet industrial, want to be, and they grab whatever they can get of industrial output, so they are not at all innocent bystanders.

Then also, it is no more possible for an industrial society to 'de-construct" overnight as the eco-extremists want, than it is for a non-industrial society to become industrial overnight, as the chinese are trying. Both involve huge disruptions and trouble.

In the process, many hasty mistakes are made, and a lot of un-necessary pain and death will result.

The people demanding that seem to be saying "It's not my problem, you have to handle it, I'M all right, Jack". Not exactly helpful, I'd say.

* the introduction of very high flying commercial aircraft is a pretty good match for the point in time at which the GW folks say the problem really "took off".... i.e. the 1940-1960 time period.

Evan
07-27-2008, 11:33 PM
My whole point was that if you accept, AS HE DOES, the idea of global warming as a result of burning carbon etc, it makes NO SENSE to then turn around and ban one promising alternate source of energy because you think it may add some heat.

"Some heat" is at least DOUBLE the energy provided for use and that doesn't include the energy used to produce the solar cells. That raises it to perhaps triple over the lifetime of the cells. And that doesn't take into account what that energy could have been used to produce/run etc if it hadn't been used to make solar cells in the first place. It's just like accounting, you have to count the initial cost and the cost of diverted funds when calculating the amortized cost of anything.

On top of that the retained heat is a direct contribution to the environment and is NOT dependent on the greenhouse gasses to produce a problem.

I never mentioned banning anything. You have a bad habit of continually putting words in my mouth that I never said. What we need to do is recognize the cost of every alternative to the mainstream energy sources. That is not currently the case with respect to solar electric power. To do so will change the attractiveness of the technology and may make other alternatives more viable.

I for one have started accumulating a few simple items to explore the practicality of putting up a vertical axis wind turbine to generate electricity that will be used directly to assist in heating my home. This is by far the easiest option for wind power as it requires virtually no infrastructure other than the turbine itself. The power is wired to a resistance heater. That's it. No batteries or controllers, nothing extra. Any heat it produces is added to what my other heat sources produce. A resistance heater is 100% efficient in converting electricity to heat and it cares not a bit about ac, dc, hertz or volts up to it's rated limit.

BTW, jet aircraft almost certainly are a COOLING influence because of the clouds that they create from the contrails.

gmatov
07-28-2008, 01:10 AM
"BTW, jet aircraft almost certainly are a COOLING influence because of the clouds that they create from the contrails."

That is asinine. A jet plane, a 747, hauls and burns over 50 thousand gallons of fuel to get you and 3 or 4 hundred people and some cargo a few thousand miles toward your destination.

You make clouds, supposedly you deflect energy from reaching the Earth, warming it up. By the same token, reflectivity keeps the heat ON Earth, doesn't get back into space.

Only the airline or petroleum industry would use such arguments. "All our pollution is good for the Earth."

Wonder what the effect is of the 747 that approaches Heathrow with an excess 10 thou gallons of fuel, dumps it because they DON'T want to crash with excess fuel that can ignite in event of a belly landing.

That fuel contaminates land for miles around the airport. If it is agriculture land, it quits producing. Contaminated.

We need more of THAT?

Cheers,

George

Evan
07-28-2008, 03:57 AM
BTW, jet aircraft almost certainly are a COOLING influence because of the clouds that they create from the contrails."

That is asinine. A jet plane, a 747, hauls and burns over 50 thousand gallons of fuel to get you and 3 or 4 hundred people and some cargo a few thousand miles toward your destination.

I drove to California some years ago to visit my Dad. On the way I stopped overnight at Grant's Pass, Oregon. The next morning I woke up, fired up the Toyota and hit the road south. As I was driving I noticed a passenger jet fly overhead from east to west. It left a nice continuous contrail across the otherwise clear sky. As luck would have it the upper air winds were blowing due south at exactly the same rate I was traveling. As I drove I observed that the contrail did not dissipate. Instead it gradually grew fatter, thicker, darker and wider. I paced it for the next 5 hours down the Central Valley to Sacramento. By the time I had to turn west that puny contrail had turned into a high level cloud stretching from horizon to horizon and at least 50 miles wide. This is not a rare occurrence. I frequently see contrails act as seeds for cloud formation.

As it happens there was an unusual one time confirmation of this effect. In the days after 9-11 the skies over the US cleared dramatically. Hours of sunshine hit record levels during that week and it exactly coincided with the grounding of all aircraft. As soon as they started to fly again the hours of sunshine at all reporting stations returned to normal contemporary values.

So, how much effect was produced by that one aircraft that I saw on the way to Berkeley? Can it match up to the fuel a 747 carries?

If it had not seeded the upper air the cloud I observed would not have formed. None did except for the one that originated from the contrail. As I wrote, it was perhaps 50 miles wide and stretched from horizon to horizon. At that altitude the horizon is about 100 miles distant on either side. That works out to an area of 200x50=10,000 sq miles. Lets calculate it in a way that can be compared directly to a 747 in flight, by horsepower. One square meter of the earth receives about 1.5 horsepower worth of energy per hour from the sun. Clouds are very effective at reflecting that energy with an efficiency of about 80 to 95 percent on the top side. So, for at least five hours that I observed it that cloud reflected perhaps on average from a cloud bank half the final size I observed, or 5000 sq miles. Of course I suspect the cloud didn't end just beyond my view but let us assume it did.

The solar energy that falls on one square mile is about 3.8 million horsepower per hour. So, that cloud was reflecting around 20 billion horsepower of solar energy back into space at the same time that plane, assuming it was a 747, was burning fuel in engines that have a cruise output of about 65,000 horsepower. Horsepower translates directly to heat, 746 watts. The cloud reflected about 300,000 times more heat back into space than the 747 used during the same time period.

Still think it's asinine?

J Tiers
07-28-2008, 08:19 AM
"BTW, jet aircraft almost certainly are a COOLING influence because of the clouds that they create from the contrails."

By the same token, reflectivity keeps the heat ON Earth, doesn't get back into space.

That fuel contaminates land for miles around the airport. If it is agriculture land, it quits producing. Contaminated.
We need more of THAT?
Cheers,
George

Preach it, Bro.

Gotta love aircraft..... possibly the least efficient means of transport known to mankind...... All they have to recommend them is speed, the first love of any manager is FedEx... "get that thing here fast, so we can wait for the rest of the stuff we need before we can use it".....

They are fun if you fly your own.

Contrails persist for a few minutes to a few hours in the best conditions.....all you have to do is look. A few may persist longer, others much shorter. I watch them, I see them dissipate. Big deal. THAT's gonna help a lot, it DOES reflect both ways.... giving some light a second chance to convert to heat. :rolleyes:

The water vapor placed up there (un-natural) is a far more potent greenhouse gas than CO2. It is put in an ideal place to block emission of heat from a wide area. The same amount lower down would have far less wide-angle effect.

And that is by NO MEANS the only effect that has been receiving short shrift from the howling mobs following the "GW Mullahs" (insert name of favorite crusade preacher if desired). There are others with no relation to aircraft.

Those others certainly INCLUDE side effects of the less-polluting power sources, like wind and PV and tide power, or harnessing ocean currents (could cause europe to freeze).

Then also, take a trip around an airport..... An airport smells like only ONE other place I recall ever being....... The crypts of a european catholic church, where thousands of candles may be burning.... Half-burned aviation fuel is a stinking miasma all around the airport. The smell is enough to give you a headache if there are a lot of takeoffs.

ONE takeoff of a smaller jet produces visible clouds of brown smoke, equal no doubt to a huge number of the current much cleaner cars....

At least aircraft have come up in discussion, and the adverse effects are now drawing comment.

Others have noticed the apparent correlation between the rate of GW and the advent of aircraft, and then high altitude jets.

Evan
07-28-2008, 08:51 AM
Contrails persist for a few minutes to a few hours in the best conditions.....all you have to do is look. A few may persist longer, others much shorter. I watch them, I see them dissipate. Big deal. THAT's gonna help a lot, it DOES reflect both ways.... giving some light a second chance to convert to heat.

On the contrary, it has been studied and contrails often form what are now called "contrail clouds". The jury is out on whether the net effect is warming or cooling. They tend to dissipate at night as the temperature drops and the barometric pressure rises. That means the net effect is weighted toward stopping sunlight rather than holding in heat.


Contrails are a concern in climate studies as increased jet traffic may result in an increase in cloud cover. Several scientific studies are being conducted with respect to contrail formation and their climatic effects. Cirrus clouds affect Earth's climate by reflecting incoming sunlight and inhibiting heat loss from the surface of the planet. It has been estimated that in certain heavy air-traffic corridors, cloud cover has increased by as much as 20%. Since contrails can spread out and essentially become cirrus clouds, it is felt that contrails may affect the planetary climate in similar ways. Other studies are underway to better understand the role that jet exhaust itself plays in modifying the chemistry of the upper levels of the atmosphere.

See here: http://www.wrh.noaa.gov/fgz/science/contrail.php

garyphansen
07-28-2008, 10:39 AM
"I for one have started accumulating a few simple items to explore the practicality of putting up a vertical axis wind turbine to generate electricity that will be used directly to assist in heating my home. This is by far the easiest option for wind power as it requires virtually no infrastructure other than the turbine itself. The power is wired to a resistance heater. That's it. No batteries or controllers, nothing extra. Any heat it produces is added to what my other heat sources produce. A resistance heater is 100% efficient in converting electricity to heat and it cares not a bit about ac, dc, hertz or volts up to it's rated limit."

Evan: I for one am very interested in this and hope you will keep us informed on your progress. I see this concept as the only REALLY practical use for wind powered electric. The prices of home wind electric around here has dropped to about $15,000. That means that the pay back, break even point would be in about twenty to thirty years depending on the cost of maintenance. However, I feel that this concept could have a much shorter payback time, and could actually be practical. Gary P. Hansen

Evan
07-28-2008, 11:02 AM
Here is a taste. Its a brushless supermagnet alternator with one moving part, zero maintenance. It puts out 110vac at 60 hz at only 260 rpm with a current of 250ma.

The armature I salvaged from a $20 ceiling fan and the rotor is made from aluminum, Lexan, surplus NIB magnets and some 1/4" bent and machined key stock for the pole pieces. If I rewind it it will put out a lot more current as it is resistance limited by the windings.

http://vts.bc.ca/pics4/alternator.jpg

Lew Hartswick
07-28-2008, 11:09 AM
I for one have started accumulating a few simple items to explore the practicality of putting up a vertical axis wind turbine to generate electricity that will be used directly to assist in heating my home. This is by far the easiest option for wind power as it requires virtually no infrastructure other than the turbine itself. The power is wired to a resistance heater. That's it. No batteries or controllers, nothing extra. Any heat it produces is added to what my other heat sources produce. A resistance heater is 100% efficient in converting electricity to heat and it cares not a bit about ac, dc, hertz or volts up to it's rated limit.
I had that idea when i built the house for my parents back about 35
years ago. I ran a seperate set of outlets around the house to a
transfer switch so they could be switched from the service entrance
to another input. This was to be some form of low quality electricity,
such as wind or solar to be used as strictly heat. It's still there but hasent
been put to use, I moved away (1800 miles) and the parents are dead.
My brother still lives there but is not "in to" that sort of thing.
I still think it's a good idea.
...lew...

J Tiers
07-28-2008, 09:57 PM
That "study" does not accord with observations around here......

Contrails visible here often dissipate, at least to visible observation, within minutes. Sometimes while the aircraft is still visible. This is not a "blowing away" or dilution, the contrail is well-formed, but simply fades out a certain distance behind the aircraft as if it evaporated (which it likely did).

I have seen pictures of a crosshatched sky of contrails, but that does NOT seem to happen here. They are gone in relatively short order.

It also is not the only effect of aircraft. Water vapor, CO2, unburned hydrocarbons, and heat are all deposited in a place where there is no natural process regularly depositing them (aside from large smoke plumes, if they reach that high).

You have previously stated that mixing is sufficient to dilute the "materials" deposited at high altitudes fast enough to prevent a problem.

It would seem that if mixing is that vigorous (which doesn't seem to be so true) that it would move the water vapor out as well.

So which is it? They can't BOTH be right.....

Evan
07-28-2008, 10:21 PM
You have previously stated that mixing is sufficient to dilute the "materials" deposited at high altitudes fast enough to prevent a problem.

So, you are putting more words in my mouth that I did not say. What I did say was that the mixing may be slow but it does mix. I never said anything about diluting anything. I'm not even sure what that is supposed to mean. Further, we aren't talking about the same part of the atmosphere. Passenger jets fly below 45000 feet. The previous discussion was about the upper reaches of the atmosphere where the loss of light elements such as helium occurs. There is no commonality between these discussions.

JRouche
07-28-2008, 10:25 PM
I was thinking of this thread today while out doing yard work and these jets came over head. They were flying in all day. Must be something scheduled here. We get them all the time but never in pairs. And some really big jumbo liner looking things came in to, unusual for here.

But what I thought was kinda odd was the trails. They were mostly on the right side of the aircraft. For most of all the eight pairs that came in today. Why only, or predominantly on the right side. Kinda odd.

Oh, and these lil trails arent helping much to offset the diesel burned by these guys. Dont imagine they are sippin the fuel. And loud!!! Oh man, as they just idle by they sound like they are rippin up the sky, tearing it in half.. JR
http://img.photobucket.com/albums/v366/Jrouche/jets2.jpg

http://img.photobucket.com/albums/v366/Jrouche/jets.jpg

J Tiers
07-28-2008, 10:30 PM
Those vapor trails are different. They are from the differing pressure and circulation over the wings........ Not from the engines, and not adding anything to the air.

You often see them in aerobatic shows, as the maneuvers cause low and high pressure areas around the wings.

being on one side would probably be due to banking and the resulting distribution of pressure.

Must be something up......... heard a loud helicopter today, and eventually a big troop carrier came lumbering overhead. Never saw one here before. Maybe it will be an interesting election!

..

J Tiers
07-28-2008, 11:07 PM
The previous discussion was about the upper reaches of the atmosphere where the loss of light elements such as helium occurs. There is no commonality between these discussions.

http://bbs.homeshopmachinist.net/showthread.php?t=22644&highlight=water+vapor+aircraft

Page 2 on usual display.

Extensive discussion of diffusion, mixing etc of aircraft-injected CO2 and water vapor.....


There is too much mixing going on for different gasses to stratify in the atmosphere. They stay well mixed.

That surely seems to be saying that the CO2 and vapor will be well mixed and so circulated down to the surface....... but it does seem to depend on the meaning of the word "is"...................:rolleyes:

Evan
07-28-2008, 11:16 PM
The amount of mixing it takes to prevent stratification of individual elemental gasses is minute. Brownian motion is sufficient. Slow, but sufficient. In the atmosphere below 50,000 feet weather systems provide very turbulent conditions that ensure that the gasses are well mixed. Thunderstorms reach to that level. The composition of the atmosphere from ground level to about 50,000 feet does not vary to any significant degree.

So, what does this have to do with anything?

Rich Carlstedt
07-28-2008, 11:43 PM
[QUOTE=J Tiers]I
My whole point was that if you accept, AS HE DOES, the idea of global warming as a result of burning carbon etc,
it makes NO SENSE to then turn around and ban one promising alternate source of energy because you think it may add some heat. ..................
I realize that you don't accept 'global warming" at all. [quote]

I never said I don't accept GW.. I don't accept "man-made" GW.
The case has never been proven.Sorry, but "concensus" is not PROOF
IT Never has been in "true" scientific study!
Classic Science demands repeatable experimental results from multiple sources, and "OPEN" discussion.
Neither has been true of the GW crowd.
It is completely contrary to my scientific and engineering background.
It IS POLITICAL , and thus, without logic or basis.
Opposers are subject to INTIMIDATION, not scientific discourse.

First GW advocates deny simple princiiples, like Earth's cycles
Second, they have absolutely no idea of how much methane and CO2 is released by the oceans.
This is compounded by the insanity now of telling Wisconsin that we have TOO many cows!,
and yet they ignore the 2 million Bison that roamed the plains 125 years ago.

Next, is the absolute lack of common sense.

Lets apply this to a practical experiment.
lets take a 200 pound cast iron skillet and light a match under it.
How long do you think you have to burn the match to get any noticable increase in temperature.
You may never get a increase in temperature
The reasons are several, one is the mass of the object to be heated versus the energy source.
Next is the non heated surface becomes MORE radiant as temperature even try to rise.
Third, the energy dispensed may not be enough to raise the temperature to a measurable degree,
in other words, the match goes out !
The Earth is a HUGE Mass compared to the heat .

The belief that we can predict temperatures 100 years from now, when we don't even know what
next winter will be like is the absolute epitome of arrogance.


LASTLY, where are they (greenies) now with the fires in California ?
According to a news report on the TV, the fires have created more pollution than all the cars
in the US...So why isn't Arnold buying Carbon credits ?
Why not demand that those who live there, pay the rest of us for their folly
Because it does not fit the political agenda..

Rich

The greatest green house gas is...........water vapor..
It makes CO2 look like a pauper
we can't even seed clouds during drouts like that predicted by Popular Science over 50 years ago
and yet we can (according to greeenies) make the oceans rise 12 feet ..give me a break

J Tiers
07-29-2008, 12:20 AM
So, what does this have to do with anything?

To you, apparently nothing.

I can stand it if you can............. What you think hardly affects me, unless I feel interested in a discussion.

If you inject a greenhouse gas (or two or three) in the atmosphere at a high level, in amounts and concentrations that are not naturally put there, then you start with an imbalance that is new, ADDED to whatever natural processes are at work. Even if it mixes (mixing UP and down, BTW), the likelihood that there will be significantly MORE of it up where it will be nice and effective as a blockade for heat is increased relative to NOT injecting it.

By the usual argument, it takes only a minute change, as it is a balance, and the change in deposition at high altitudes is certainly at least "minute".

Ground level can affect only local areas until it diffuses/mixes. At high altitudes, the area that its "shadow" covers is greater.

Solar input is primarily in one direction at any given time, and for part of the day. shadows may be on areas of low or high reflectivity in the visible. Re-radiation is 24/7, and in all directions.

Oceans may carry heat via currents from areas of high input to areas of low transmission.

Radiation is over the entire angle of sky "visible" to the radiating object. So a high altitude "blockade" is "visible" to more surface area than lower level stuff, and the effect is "right away" if the material is constantly renewed.

A lot of planes fly every day....... does the mixing occur fast enough to completely dilute the materials before more is deposited? I don't know the answer, but I suspect it isn't easy to determine, and could be made to seem any way one might want by choosing data.

And, we almost surely have no way to positively determine the high level concentrations prior to modern times, except by assuming perfect mixing and using the old core samples trapped gas.

If you can attack solar energy via PV for heat input, without a rigorous analysis, than I can do the same for "disproportionate high altitude deposition of greenhouse gases by aircraft". Either could make an interesting paper title..... if the howling mob didn't shout it down...........

You have some data (no numbers on the graphs, where did they come from?), and I have an interesting co-incidence of use of aircraft in a big way, and the documented and agreed acceleration of global warming......

I still think that burning coal, if it really is affecting GW, is more exponential in effect, as it both adds heat, AND continuously increases the blocking of re-radiation, retaining more and more heat.

Any heating from PV panels would be only a linear effect of adding heat. May not be good, but is not as bad. Plus there are other adjunct sources of power as well, not all of which may be wise to get into.

Made to choose between them, I know which would be my choice...... The third choice is akin to grass huts and massive die-off.

Evan
07-29-2008, 01:38 AM
If you inject a greenhouse gas (or two or three) in the atmosphere at a high level, in amounts and concentrations that are not naturally put there, then you start with an imbalance that is new, ADDED to whatever natural processes are at work. Even if it mixes (mixing UP and down, BTW), the likelihood that there will be significantly MORE of it up where it will be nice and effective as a blockade for heat is increased relative to NOT injecting it.

What makes you think green house gasses are at high altitude? The transparency of the atmosphere to infrared radiation is determined only by the density of the various constituent gasses. Nearly all the absorption takes place below 20,000 feet since that is where the majority of water vapor is. The same hold true for CO2 and any other gas. It's the reason they built the Canada/France/Hawaii Telescope on top of Mauna Kea. It's above the majority of water vapor so it can make better observations in the Infrared. In fact, at almost 14000 feet 90 percent of the water vapor in the atmosphere is below the summit as is 40% of the other greenhouse gasses. What happens at 40,000 feet is not an issue of greenhouse gasses but of shadowing or reflecting direct radiation or indirect reradiation from below.


By the usual argument, it takes only a minute change, as it is a balance, and the change in deposition at high altitudes is certainly at least "minute".

Ground level can affect only local areas until it diffuses/mixes. At high altitudes, the area that its "shadow" covers is greater.

Nope, basic geometry. The sun's rays are effectively parallel

Proof, my photo.

http://vts.bc.ca/pics4/rays.jpg

Solar input is primarily in one direction at any given time, and for part of the day. shadows may be on areas of low or high reflectivity in the visible. Re-radiation is 24/7, and in all directions.

Nope. I can see the sun anywhere it is above my horizon. The rays of light are effectively parallel because of the distance to the sun so the distance between me and an obstruction here on earth isn't relevant. As you drive along the apparent position of the sun in the sky does not seem to change. The shadow of something high in the atmosphere is the same size as the shadow of that same thing low down. It doesn't cover more area because it is higher.


Oceans may carry heat via currents from areas of high input to areas of low transmission.

So what?

Radiation is over the entire angle of sky "visible" to the radiating object. So a high altitude "blockade" is "visible" to more surface area than lower level stuff, and the effect is "right away" if the material is constantly renewed.

Nope. A high altitude object subtends a smaller apparent angle than a low altitude object as seen from the ground. As an example, a 25 cent coin held 9 feet away will blot out the moon or the sun. Place it further and it doesn't. The effect is exactly opposite of the effect on the sun because we are now dealing with short distances from the source. When you move further away from the source the shadowing or reflection grows smaller by inverse square

A lot of planes fly every day....... does the mixing occur fast enough to completely dilute the materials before more is deposited? I don't know the answer, but I suspect it isn't easy to determine, and could be made to seem any way one might want by choosing data.

It isn't relevant compared to the energy blockade cause by clouds. Blocking the energy over hundreds of square miles and reflecting about 90 percent of it into space (or back to earth) totally overwhelms any other effects that may occur. The decrease in transparency caused by a rise in a greenhouse gas isn't total. It isn't even large. It's tiny and would take perhaps hundreds of years to equal the effect of completely blocking the sun with a cloud formation that lasted only an hour.

And, we almost surely have no way to positively determine the high level concentrations prior to modern times, except by assuming perfect mixing and using the old core samples trapped gas.

Not relevant. Greenhouse gasses are mainly at low altitudes.

If you can attack solar energy via PV for heat input, without a rigorous analysis, than I can do the same for "disproportionate high altitude deposition of greenhouse gases by aircraft". Either could make an interesting paper title..... if the howling mob didn't shout it down...........

No, you can't. On the other hand my calculations are based on very well quantified and qualified information. It's simple 4 function math.

You have some data (no numbers on the graphs, where did they come from?), and I have an interesting co-incidence of use of aircraft in a big way, and the documented and agreed acceleration of global warming......

Correlation never implies causation and cannot be used to prove anything. That is the most basic tenet of statistics.

I still think that burning coal, if it really is affecting GW, is more exponential in effect, as it both adds heat, AND continuously increases the blocking of re-radiation, retaining more and more heat.

Any heating from PV panels would be only a linear effect of adding heat. May not be good, but is not as bad. Plus there are other adjunct sources of power as well, not all of which may be wise to get into.

Adding heat increases the evaporation of water which increases the amount of water vapor in the air which traps more heat etc. That is the main multiplier effect that follows ANYTHING that increases the temperature at sea level.

gmatov
07-29-2008, 03:19 AM
Evan,

See, guys like you are all one way or the other, depending on which side of the argument you are on.

"The solar energy that falls on one square mile is about 3.8 million horsepower per hour. So, that cloud was reflecting around 20 billion horsepower of solar energy back into space at the same time that plane, assuming it was a 747, was burning fuel in engines that have a cruise output of about 65,000 horsepower. Horsepower translates directly to heat, 746 watts. The cloud reflected about 300,000 times more heat back into space than the 747 used during the same time period."

That cloud was shielding, or, "reflecting around 20 billion horsepower of solar energy back into space".

Only MAJOR problem with that is that Al Gore and all the other Global Warming alarmists say that the buildup of GREENHOUSE GASES are INSULATING the Earth, preventing heat from escaping back into the absolute Zero of Space.

Why can it PREVENT the admission of heat, which is good, as the Airlines will swear, but not deter the release of heat FROM the planet back into Space, which is the Gore Gambit?

I won't go back far enough to quote the air qualities of cities in the weeks after 9/11, but mention has been made that the air quality was much better for a little while.

WHO, and I am asking seriously, knows just how many gallons of fuel ARE consumed by jet airplanes? From my Googling, jet airplanes consume more fuel than most other means of consumption.

Yet the automobile driver is depicted as the HOG. If we could only get the CAFE up a mile per gallon, all would be well.

Before the reduction in airlines flights were instituted, nearing bankruptcy, there were about 35,000 flights per day originated, and that may have been a local area thing, hundreds of millions of gallons per day burnt, all of which made those cute contrails that reflected ALL that energy back into space, NONE of which, we have read here, insulates the heat we have here from exiting INTO space.

I think I am going to clean out my wall stud spaces, fill them with contrail stuff, as it seems to be selective, allows heat out, but does not allow heat in.

Nah, that would be bad. Heating season, house would lose heat, cooling season, wouldn't even have to run the AC. One way insulation. A heat rectifier. Who'd a thunk you could make such a thing?

And Jet Planes make it with not a thought of it. Why don't all them airlines brag about how much they are combating GW?

Probably because they cry that they have to pay 10 to 20 cents MORE per gallon than their locked in prices since their options expired.

Couple hundred million here, couple hundred million there, comes bankruptcy. Equate that couple hundred million BUCKS to gallons of fuel, and 20 cents or so, and they are bankrupt, seems to mean they burn BILLIONS of gallons of fuel.

Yet, you, a peon, are the prick driving up the price. Speculators are absolutely a minute amount of the rise.

Bridge, anyone? I have a nice one in Brooklyn for sale, cheap. Pics on request.

Cheers,

George

Evan
07-29-2008, 05:59 AM
Yet, you, a peon, are the prick driving up the price. Speculators are absolutely a minute amount of the rise.


Your lack of understanding of the issue is equaled only by your eloquence of written expression George. What will you do if you learn to read? Studying science would be a good place to start.

A cloud is not a greenhouse gas. In fact it isn't composed of any sort of gas at all but of droplets of liquid water. Water vapor is invisible and cannot be seen. It does not make a mist, a fog or a cloud. If it condenses to liquid water then it is no longer water vapor and the nature of the substance changes along with it's phase.


Why can it PREVENT the admission of heat, which is good, as the Airlines will swear, but not deter the release of heat FROM the planet back into Space, which is the Gore Gambit?

A cloud is a reasonably good reflector of heat but it is a much better reflector of visible light where the majority of incoming radiation is concentrated. My specific example occurred in the daytime when the sun was shining. If you are outside and standing in the sun you may feel warm. If a cloud passes between you and the sun you may feel cooler while in the shadow. That is the effect to which I refer in my example.

Those things that were illuminated by the sun previous to being shadowed by the cloud are indeed reradiating SOME of that energy as long wave radiation since they were warmed previously by the direct sunlight. However, the intensity of such radiation is a function of temperature of the object that is doing the emitting. It varies by the square of the temperature of the object, the hotter it is the greater the emission of radiation per second and the shorter the wavelength of that emission.

To understand this one needs to appreciate the difference between temperature and heat. A bathtub of warm water contains far more heat than a candle flame but the candle flame is at a far higher temperature. For that reason the candle flame glows at visible wavelengths but the bathwater does not.

During the daytime heat arrives from the sun in the form of visible radiation. It is effective at warming the surface of the earth. The warmed surface then reradiates some of the heat but at a much longer wavelength due to its much lower temperature. Consequently it also radiates much less energy per second than it received. The balance of radiation when a cloud is formed in the daytime is overwhelmingly one of cooling as the cloud efficiently reflects the intense solar radiation back out into space at visible wavelengths to which the atmosphere is largely transparent. The cloud that I witnessed to form from a jet contrail was seen by myself and reported here as being in the daytime. The numbers that I calculated are correct in magnitude. They do ignore the amount of radiation that was prevented from escaping due to the interposition of the cloud in the sky. However, during the daytime that radiation from the earth is not the equal of the radiation from the sun. In fact, the difference is orders of magnitude.

It is the reason we are not all fried to a crisp in short order. Were it not for our cloudy skies the planet would be a flambé.

Of course, the balance is restored at night when the clear skies have an effective temperature of about -70f and the surface radiation is partly able to escape to space. Then a cloud still reflects radiation from below on the surface and helps to keep us from freezing in the dark. However, the amount of energy that a daytime cloud reflects back to earth will never equal the amount of energy that it reflects to space from the sun. It doesn't even come close. The net effect of clouds is to cool the planet, not keep it warm. It is the greenhouse gasses in the atmosphere that prevent this planet from becoming a ball of ice.

As for the atmospheric pollution caused by the burning of jet fuel, that is an issue. But it is a separate issue, one of air quality, not global warming or its lack.

J Tiers
07-29-2008, 08:36 AM
Now you are being either silly or intentionally dense.

Just to begin with:


What makes you think green house gasses are at high altitude?

Possibly the fact that we are talking about aircraft flying at "high altitudes" and depositing greenhouse gases there.... Might have some "peripheral relevance".....................:rolleyes:


Nope, basic geometry. The sun's rays are effectively parallel

Proof, my photo.

Not relevant..... as the earth turns, the shadow of a high object moves over a greater area of the earth than the shadow of a very low object. it therefore may affect (or not) differing areas, either enhancing or reducing its effect depending on the nature of the absorbers or emitters it shadows. A low cloud, or smog, affects only the area below it. If that is a high absorption area, you "win" if a low absorption area, it isn't much help. Obviously the reverse for emissions.

Since the cloud stays in the same place relative to the emitters, but "moves" in relation to the sun as the earth turns, it is perfectly possible for the effect on emission to exceed the effect on absorption.

On average, a given cloud when high may block more radiation than if low, if the area directly below is low emission (cooler) but areas of high radiation are "visible" when the cloud is higher.

A matter of 90% effect on a small area vs a smaller effect per unit area over a larger area. All depends on the areas in question.

Point being that materials at high altitudes, as they spread out, may become more effective as a shadowing means, either for incoming OR outgoing radiation.

The subtended angle may be smaller if higher, but as compensation, that subtended angle is a part of the "sky angle" for more area.

Since this is all a matter of small changes affecting a balance, there is no help in claiming irrelevance due to small effect.


Not relevant. Greenhouse gasses are mainly at low altitudes.

Again, we are specifically discussing G-G deposited by aircraft. Anything else is just "noise" in this discussion. I am very surprised you were not aware of that, given recent statements.....


Correlation never implies causation and cannot be used to prove anything. That is the most basic tenet of statistics.

Gosh, Evan, it is the most BASIC TENET OF THE ENTIRE FIELD OF SCIENCE that when you see correlated things, you go look to find out if they are related..... because there is a decent chance you are seeing a real relation. Much more so than if you do NOT see a correlation....

UNBELIEVABLE THAT YOU WOULD HAVE SAID THAT. STAGGERING AND ALMOST UNTHINKABLE IN ITS FLAT-OUT IGNORANCE.


I'll leave the rest of your misinterpretations, word twisting, etc for YOU to figure out. I feel sure that you will learn in time......

Evan
07-29-2008, 09:15 AM
Possibly the fact that we are talking about aircraft flying at "high altitudes" and depositing greenhouse gases there.... Might have some "peripheral relevance"....................

It is the density of the entire column of the gasses that determines how much energy they absorb. The density at 40,000 feet is 1/5th what it is a sea level so the absorption at that altitude is correspondingly less. The change in density with altitude also isn't linear. At 55,000 feet it is down to 1/10.


as the earth turns, the shadow of a high object moves over a greater area of the earth than the shadow of a very low object. it therefore may affect (or not) differing areas, either enhancing or reducing its effect depending on the nature of the absorbers or emitters it shadows. A low cloud, or smog, affects only the area below it. If that is a high absorption area, you "win" if a low absorption area, it isn't much help. Obviously the reverse for emissions.

A moving shadow still only covers the same total area as one that is stationary, high or low. Since we are talking about many such shadows the shadow effects will average to be the same, high or low.


Point being that materials at high altitudes, as they spread out, may become more effective as a shadowing means, either for incoming OR outgoing radiation.

Using what system of geometry?


Gosh, Evan, it is the most BASIC TENET OF THE ENTIRE FIELD OF SCIENCE that when you see correlated things, you go look to find out if they are related..

Really? That would be bothersome. Many unrelated events are correlated. Still it remains: Correlation does not imply causation.


UNBELIEVABLE THAT YOU WOULD HAVE SAID THAT. STAGGERING AND ALMOST UNTHINKABLE IN ITS FLAT-OUT IGNORANCE.


I'll leave the rest of your misinterpretations, word twisting, etc for YOU to figure out. I feel sure that you will learn in time......

I note you haven't been addressing your rather blatant mistakes and assumptions that I have rebutted.

Rustybolt
07-29-2008, 05:16 PM
Considering the sheer volume of atmosphere from the ground to say 45,000 feet, I sincerly doubt that the activity of a few thousand aircraft are going to make that much difference, if any. If it did Chicago would be unlivable. It may in fact be unlivable, but for different reasons.


And for the person who complained about fuel dumping; Oftentimes if there is trouble and a plane has to turn back after just taking off, fuel has to dumped because the plane can't land with the weight of fuel onboard.

J Tiers
07-29-2008, 10:41 PM
Considering the sheer volume of atmosphere from the ground to say 45,000 feet, I sincerly doubt that the activity of a few thousand aircraft are going to make that much difference, if any. If it did Chicago would be unlivable. It may in fact be unlivable, but for different reasons.


And for the person who complained about fuel dumping; Oftentimes if there is trouble and a plane has to turn back after just taking off, fuel has to dumped because the plane can't land with the weight of fuel onboard.

Naturally, necessity does not make fuel dumping less damaging, it just makes it more likely.

A big load of fuel dumped is far more unburned hydrocarbon pollution than many normal flights combined. Normally only a small percentage is unburned. Jets are pretty good about that now. They used to smoke like sinners.

Evan has made much of the "small tilt" theory over time, and that is what you are ignoring. He has asserted a change from a "relatively small" area of solar cells, with a reflectivity "somewhat less than" the assumed reflectivity of the ground.

And there is point to that. My quarrel is with using that as a reason to avoid a technology which is considerably "less bad" than doing nothing.

In any case, it may not TAKE much to tilt the equilibrium.

One might make your statement about many things, such as cars, for instance. They ar small and the world is big. But they HAVE caused pollution, and made areas quite smoggy.

They are less bad than some other things.....

A car "breathes" a certain amount of air, and can therefore "burn" only so much fuel (not, btw, 100% carbon) in the oxygen contained in it.

A common 2 liter displacement engine will burn fuel in 2 liters of air over 2 revolutions (if 4 stroke cycle). If it operates at a cruising RPM of about 3000, each minute it will burn fuel in 3000 litres of air, or about 3 cubic meters. In a 30 minute journey, that is about 90 cubic meters. At 1 kg per cubic meter for air, and 15kg air per kg fuel, that's about 6 kg fuel, maximum. Likely less.

A single jet engine moves 90 cubic meters through it in a very short time. Air goes through at a rate measured in cubic meters per SECOND. A considerable amount of that (not all) goes though combustion. One could calculate a total from the thrust figures...... and exit velocity. Or from fuel consumption rates.

Doing a bit of estimating and some calculations might come up with the number of "average car-hours" equal to one jet engine through a single takeoff and climb-out. A different figure would apply to cruise..... The numbers are probably available, someone has no doubt done that, and if it isn't TOO many cars, the numbers may not have been suppressed.

Point being that aircraft burn a lot of fuel. And they operate in a part of the atmosphere which in the natural sequence of events would get exhaust only through circulation, after dilution and partial settlement, absorption, etc of exhaust components at the surface.

My point is that there is NO PRECEDENT for the continuous, direct deposition of exhaust up there, in the history of the earth. There are cataclysmic events, and there is natural circulation. Even large chimneys are not quite as good at placement of exhaust.

But, there are, I seem to recall, about 12,000 various active commercial jets, and an unknown number of military jets. The commercial jets make a lot of flights per day, with some flying for many hours at high altitudes on intercontinental flights, or longer "domestic" flights. They fly at all hours of the day.

International flights are common, since that is the only practical method of intercontinental travel at present. Passengers. or expedited freight as Fed-EX, UPS, DHL, etc.

it would be very surprising if aircraft had NO effect.

Given the "small tilt" theory, just a relatively minor adjustment to an equilibrium is enough to send it one way or the other.

Since the general effect, if any, of fuel burning is apparently to enhance global warming, it is reasonable to consider that doing the same thing (burning fuel) in a different place (high altitude) may likely have a similar effect of enhancing global warming. it might be a worse effect than at lower altitudes, since it will necessarily take longer to reach any "carbon sink" on the surface than exhaust from surface burning does.

Other effects are possible, but if an effect is already known to be negative elsewhere, one is not wise to decide off-the-cuff that it is probably beneficial in a new place. Not without a very good reason, and preferably actual knowledge.

When the advent of heavy use of aircraft (as of ~WW2) coincides with an increasing rate of warming, it surely merits investigation, unless one has a vested interest to NOT find out anything bad.

A smoking gun may simply be burning.... or it may have been fired. You have NO IDEA until you check.

Evan
07-30-2008, 01:47 AM
I wish you wouldn't use the word theory in place of hypothesis. A theory is confirmed through observation and experiment to be correct and has predictive power. As for what you are calling the "small tilt" hypothesis, it isn't just a hypothesis ("just a theory"). Weather, which is the expression of climate, is a chaotic system. This has a special meaning not related to the usual meaning of chaos. It is a system that exhibits certain properties the most important of which is a strong and often inherently unpredictable sensitivity to initial conditions. Most people have heard of the so called "butterfly effect" where it is said that it may be possible the flap of a butterfly's wings in Spain might start a chain of weather events that end up as a hurricane in Florida, or something similar. This is an apocryphal example but it illustrates the concept.

Weather is dependent on energy to drive the systems that make the weather. That energy comes from the sun. Most of that energy is stored in the oceans as heat in the water. That heat drives the evaporation of water which transfers the energy to the atmosphere and then drives the formation of active weather systems. There are possible compensatory mechanisms since the more evaporation there is the more water vapor there is in the atmosphere. While water vapor is a greenhouse gas it also appears to be self regulating. It is a negative feedback system. The increase in water vapor results in an increase in clouds which cools the planet. If this were not so then any slight increase in planetary average temperature, and there have been many cycles, would result in a runaway greenhouse effect. We would not be here to discuss it.


My point is that there is NO PRECEDENT for the continuous, direct deposition of exhaust up there, in the history of the earth. There are cataclysmic events, and there is natural circulation. Even large chimneys are not quite as good at placement of exhaust.

There most certainly is. Jets do not fly above all the weather and other phenomena. In particular large volcanic eruptions place cubic miles of CO2, sulphur dioxide and other compounds very similar to the combustion products of jet fuel in the same altitude regime that passenger jets fly in as well as higher. The result from truly large eruptions is temporary global cooling which is due in large part to dust particles placed in the lower stratosphere. One of the best recent examples was the eruption of Krakatoa which resulted in abnormally cold winters and several years without a summer. Dust particles also reflect incoming radiation back to space although not nearly so effectively as water clouds. Jet exhaust contains fine particulate carbon even now although much less than from the early model engines. That is a perfect type of seed particle to promote the condensation of water vapor to clouds. Even if no contrail forms or it forms but dissipates the seed particles remain, able to act as nuclei for water droplet formation at a later time.

Any cloud that forms and is present during the day blocks so much energy that any additional green house effect from the combustion products will be entirely swamped to insignificance. Just one large persistent cloud can reflect terawatts of energy in a day. The effect is also not random when caused by high flying aircraft. Many more flights are scheduled during the day than overnight.

Also, there is a diurnal variation in barometric pressure caused by the nighttime cooling of the atmosphere. When the air cools the barometric pressure increases and this causes condensed water to resume the water vapor phase. There are fewer clouds at night than during the day on average. As I said before, it is the greenhouse effect that prevents the Earth from turning into an ice planet. It is estimated that were the normal greenhouse effect absent the average temperature on earth would be below the freezing point and the oceans would eventually freeze to the bottom or close to it.


When the advent of heavy use of aircraft (as of ~WW2) coincides with an increasing rate of warming, it surely merits investigation, unless one has a vested interest to NOT find out anything bad.

The increase of the use of aircraft is correlated with every single thing that has also increased or decreased (negative correlation). For instance, the increase of high flying aircraft is directly correlated with the construction of thousands of square miles of runways and parking areas since WWII many of which are paved with asphalt. Those runways have an albedo much lower than the usually open fields they covered and may well be at least in part responsible for the increase in warming that seems to be correlated with the aircraft. There are approximately 2000 miles of commercial jet service runways in the US with a width of 100 to 200 feet and an unknown but larger number of smaller airports. The parking areas and taxiways are even larger than the runway areas and are almost always asphalt paved.

Also, the increase global temperatures is directly correlated with the increase in average body weight of Americans flying on those aircraft.

Any statement that uses an apparent correlation to support a position is worthless on it's own merit. It must have corroborating evidence to mean anything.

gmatov
07-30-2008, 01:58 AM
Evan,

You got me there. I am not a scientist. Nor do I think you are, but I will not tell you you should read more of the scientific literature. I read a lot but possibly not what you do.

Regardless, the temperatures on any part of the Earth which have a "Cloudy day" are cooler, on that day, than areas which have cloudless days.

That would indicate that all that "cloud cover", which you call water, absorbs photons from the sun and doesn't reach the Earth. Life on Earth would be impossible were the heat of the Sun NOT to reach the Earth's surface.

I am old enough to remember 30 years ago when the Scientists, most prestigious of the time, claimed we were in a Global Cooling, an imminent Ice Age.

It kind of depends on when kids graduate from College. If we are having hot Summers, Global Warming. Had you graduated 10 years earlier, Global Cooling.

I have no idea whether you are a 30 year old or a 60 year old. That would tell some of why you take the position you do.

As to your vertical turbine, 50 years ago, in PS or PM, split a couple 55 gallon drums vertically, attach to a column with bearings, drive your alternator.

I forget the name of that turbine but would sooner bear the liability of that than propeller blades spinning, breaking off, and going through a house 1/2 mile away.

Or, go buy a Jacob's Wind Turbine from a farm that doesn't use theirs any more.

Probably 40 years ago that I read his interview in a mag. Most efficient windcatcher is 3 bladed. Engineers after him must believe it, You don't see a wind power unit with more blades.

I don't believe we are "insulating" the Earth, as Gore and you are preaching.

If we are, have you ever considered that we will chill those areas of the Earth that already get damned cold AFTER sundown? The one time I have been in Texas, October, 50 years ago, daylight was 80 degrees, night was less than 40.

I think it is about the same here in PA, 80+ in the daytime, 50's in the night, in July.

Insulating layer of pollution, again, seems to not be working. Heat strikes the Earth in the day as photons from the Sun, hots everything up, Sun goes down, Damn, why doesn't it all stay trapped within the Ionosphere, all those insulating gases, and keep the Earth HOT overnight?

Ethiopia and other African nations with ove 120 degree heat in the day, what is the nightime temp?

Why does there not, as to you, appear to be any greenhouse gases to "insulate" those desert areas. I think those desert areas cool rather quickly after the Sun goes down.

You make some good points, but you strike me as a youngster who has been brought up with GW as your mantra.

Sorry,

George

Evan
07-30-2008, 04:17 AM
I'm 59 and retired George. Gore is an idiot and scam artist. The net effect so far of global warming isn't in hotter days and summers. It's primarily in less cold winters and warmer winter nights. That is what happens when less infrared escapes at night. That is why it isn't very noticeable to the average person. Warming can happen at either end of the temperature scale and it doesn't have to be the high end. It isn't.

The warming effect is produced by the atmosphere close to earth, not the ionosphere. You are making the same mistake as Jerry in confusing the problem of ozone depleting substances with greenhouse gasses. Some gasses are both but the actions take place in entirely different parts of the air column and the two effects are largely unrelated in nature.

Global warming is not in doubt. We have the advantage now of much better instrumentation over that of 30 years or more ago. Remote sensing from satellite is now a well developed science which was in it's infancy in the 70s.

I'll give you an example of how advanced it has become. We recently gained access to high resolution satellite photos of this valley on Google Earth. They were taken several years ago based on what I see such as a neighbor's new shed not being visible. Something is killing nearly all of our western juniper bushes. We aren't sure what it is though. It seems, according to a local forester that it may be due to an unprecedented explosion of the field vole population because of higher survival rates in the warmer winters. They gnaw the bark and kill the plant. I think, with no hard evidence, that it may be related to unusually high levels of ultraviolet during the winters and spring of the last two years since only the south facing plants are affected.

Here is the Google Earth shot of a neighbor's field. It shows that only three years ago the junipers were green and healthy. It's followed by two pictures I took this year showing the same patches I indicated in the first photo as now dead.

The point is that 30 to 40 years ago even the military could only dream of such quality in remote sensing hardware.

http://vts.bc.ca/pics4/juniper1.jpg

http://vts.bc.ca/pics2/gw2.jpg

http://vts.bc.ca/pics2/gw3.jpg

With this sort of information at our fingertips we are much better equipped to discern what is happening. Global warming is a reality. What we don't know with certainty is the cause or causes. Greenhouse gasses play a part for sure but there may be other factors too. I'm not willing to say it is all the fault of humans but I am sure we are having an effect.

J Tiers
07-30-2008, 08:28 AM
Any statement that uses an apparent correlation to support a position is worthless on it's own merit. It must have corroborating evidence to mean anything.

Twist, twist, distort......

I keep saying that a correlation between things WHICH HAVE A POSSIBLE CONNECTION "merits investigation".

You keep saying I am asserting correlation as PROOF. That is a LIE.

Among OTHER similar distortions, of course....... Such as the "small tilt"..... which you think and say that I don't agree with. I do. So do you. I use it because YOU CAN"T DENY IT.


A moving shadow still only covers the same total area as one that is stationary, high or low. Since we are talking about many such shadows the shadow effects will average to be the same, high or low.

Thank you for MAKING MY ARGUMENT.

The point is exactly that. A low "cloud" for lack of a better term, can only shadow what is directly below it. it has no influence on other areas, and so its effect is local. If local is a high absorption area, that's one thing, but if it isn't that's another.

By contrast, a high altitude deposit of GG DOES average its effect over areas of low or high absorption, indescriminately. So it is virtually guaranteed to have influence on incoming or outgoing radiation to at least some areas of high absorption.

Your argument is that it gets averaged either way. That might be so, if the distribution of low level GG were random. it is not. The non-random nature may or may nit be beneficial, but it is true.

As low level GG drift, they are likely to pass over absorbers of GG (forest, cornfields, etc), and be depleted to some degree, or be diluted by air which has been depleted of GGs by vegetation. Maybe slight effect, but certainly present.

There is NO such absorber present at high altitude. Any GG must be circulated down to be absorbed.


In particular large volcanic eruptions place cubic miles of CO2, sulphur dioxide and other compounds very similar to the combustion products of jet fuel in the same altitude regime that passenger jets fly in as well as higher. The result from truly large eruptions is temporary global cooling which is due in large part to dust particles placed in the lower stratosphere.

I mentioned cataclysmic events........ you may have not seen that in the snippet you quoted.............

A volcanic eruption is in no way comparable. Some similar compounds? sure. But cubic miles of particulate dust are not a component of jet fuel exhaust.

And, the dust falls out. The event ends, and the emissions dissipate.

Exhaust is being spewed and pumped into the atmosphere at higher altitudes every hour of every day of every year by 12,000 commercial jets, plus military. And it has been going on for roughly 50 years.

I repeat, THAT has NO PRECEDENT.


There are approximately 2000 miles of commercial jet service runways in the US with a width of 100 to 200 feet and an unknown but larger number of smaller airports. The parking areas and taxiways are even larger than the runway areas and are almost always asphalt paved.

Concrete is at least similar to your roof in reflection of light....... parking areas are NOT paved in asphalt. if they were, jets would sink in due to high wheel weights. Airports I see are essentially all white concrete.

And, the street in front of my house is asphalt. it is about 8 years old since re-paving. It is gray and resembles your roof in apparent reflectivity, due to exposed aggregate. That is quite typical.

Evan
07-30-2008, 09:13 AM
Your argument is that it gets averaged either way. That might be so, if the distribution of low level GG were random. it is not. The non-random nature may or may nit be beneficial, but it is true.

What? What makes you think that is true? Low level atmospheric mixing is rapid and complete. Your argument is based on a fallacy. The CO2 percentage content (for example) doesn't vary with location by ANY measurable degree. Apparently the scientists think so too since they are content to use a single monitoring station in Hawaii as representative of the entire planet. Neither does the content of any other constituent gasses vary regionally with the singular exception of water vapor. That however is also self regulating as the cloud is also water. You don't see a lot of clouds over very dry areas because they ARE very dry. Deserts are a case in point.

More to the point, it simply doesn't make a difference what altitude a cloud is at in terms of shadowing because of the effect of averaging. If there were some sort of difference it would be rapidly and completely averaged by the huge number of both high and low level clouds. As well, low level clouds also move.


You keep saying I am asserting correlation as PROOF. That is a LIE.

You are one to complain. You keep putting words in MY mouth that I have not said. I have not said that you are asserting correlation as proof. I am pointing out that it isn't, mostly for the benefit of others that may read this, if any are left. It is the most widely held mistaken belief bar none. It falls in the category of circumstantial evidence by which many have been falsely accused and convicted.


Exhaust is being spewed and pumped into the atmosphere at higher altitudes every hour of every day of every year by 12,000 commercial jets, plus military. And it has been going on for roughly 50 years.

I repeat, THAT has NO PRECEDENT.

It has a clear precedent.

Volcanic events are common and nearly continuous. It is one of the major hazards that passengers jets face flying over the Pacific and elsewhere.

Such dangerous and costly encounters between aircraft and volcanic ash can happen because ash clouds are difficult to distinguish from ordinary clouds, both visually and on radar. Also, ash clouds can drift great distances from their source. For example, in less than 3 days, the ash cloud from the June 15, 1991, eruption of Mount Pinatubo in the Philippines traveled more than 5,000 miles to the east coast of Africa. This ash cloud damaged more than 20 aircraft, most of which were flying more than 600 miles from the volcano.

Along North Pacific air routes, some of the busiest in the world, at least 15 aircraft (including KLM Flight 867) have been damaged since 1980 by flying through volcanic ash clouds. In the same period, there have been 80 such encounters worldwide, causing hundreds of millions of dollars in damage and lost revenue. Fortunately, no fatalities have yet occurred, but the growth in air traffic over volcanically active regions, such as the North Pacific, is increasing the chance of a deadly encounter.

http://pubs.usgs.gov/fs/fs030-97/

dfw5914
07-30-2008, 09:36 AM
The earth was at some point in the past hotter than it is now.
The earth was at some point in the past cooler than it is now.
I predict that this pattern will repeat.

Evan
07-30-2008, 10:17 AM
The earth now has over six billion people on it.

I predict this pattern will not repeat.

rotate
07-30-2008, 10:26 AM
A medium size meteor hitting earth could reset that figure very quickly :D

Rustybolt
07-30-2008, 06:00 PM
All of whom , if given 3 square feet to stand in ,would fit in the state of Missouri. We, as a species, are going to be around awhile. Get used to it.
I noticed recently the peope in southern California are causing earthquakes. Laws should be passed.

Rustybolt
07-30-2008, 06:05 PM
j.Tiers. I'll make a bet with you. I'll bet you a fifty years from now the planet will be cooler and there will be more people.

Evan
07-30-2008, 07:51 PM
Not likely. The universe will come to an end before that. At least, it will for me.

garyphansen
07-30-2008, 09:33 PM
Evan: I would bet not. Gary P. Hansen

JRouche
07-30-2008, 09:50 PM
Still a constant 78 degrees here, I love Ventura County!!!!! Saw Canada lost another ice shelf, maybe it will float down here and cool things off LOL Hot or Cold, life will go on, till it doesnt :) Im pretty deep huh???? LOL JR

J Tiers
07-30-2008, 10:13 PM
obviously the low level GG are NOT randomly distributed.

That is, quite literally, "intuitively obvious to the most casual observer".....

SOURCES of GG are concentrated. They are not evenly produced over the earth's surface.

Mixing distributes the PAST emissions.

These sources , as well as aircraft, are a CONTINUOUS source. Ground sources are relatively fixed, in that they are either LITERALLY fixed (for instance Four Corners power plant), or in the case of urban areas, the mobile sources tend to cluster.

Aircraft do tend to spread their emissions, although they do tend to be along certain paths. Still not the same as a fixed source.

The mixing effects cannot effect an effective dilution of a continuous fixed source until some point "downwind". That is fairly obvious from any sort of mixing experiment you choose to do.

For the conclusions, refer back to the prior posts, I simply am not interested in taking time to type it out in different words, or even in copying it forward.


As for volcanos, I think you are stretching a point past breakage.

Are you seriously asserting the existence of several Krakatoa or Mt St Helens events per year? Heavens above, where are the scientists and reporters?

No, the events you refer to are minor in comparison, scattered and in no way comparable to the cataclysmic eruptions.

With aircraft and other sources we have a continuous emission in the same place, or initially distributed in the same way. And the emission is 24/7/365.

Furthermore, it is direct, injected without any intermediary mixing, etc.

You have better points to make, some of which I might even admit are good arguments. Not conclusive, but decent counter-points.

Don't pound away on the losing ones.

Evan
07-30-2008, 10:41 PM
The average condition of the atmospheric gasses is well mixed, not unmixed. We would be in big trouble if it were otherwise. Humans can only stand a slight reduction in the partial pressure of oxygen before the begin to suffer anoxia. At sea level anything less than 19% oxygen content is dangerous.


Are you seriously asserting the existence of several Krakatoa or Mt St Helens events per year? Heavens above, where are the scientists and reporters?

I'm not suggesting it, it happens. Not Krakatoa, it was small large eruption. Mt. St. Helens size eruptions are fairly common and eruptions that raise ash to the lower stratosphere are very common. Right now there are 14 major eruptions in progress with two that are raising ash clouds over 30,000 feet. Mt Kilauea is releasing about 800 tonnes of sulfur dioxide every day.

[edit]

Every year volcanos put far more gasses and ash into the upper atmosphere than all the aircraft do in a decade or more. The output of many volcanic eruptions is measured in cubic miles not puny gallons.

J Tiers
07-31-2008, 08:36 AM
The average condition of the atmospheric gasses is well mixed, not unmixed. We would be in big trouble if it were otherwise. Humans can only stand a slight reduction in the partial pressure of oxygen before the begin to suffer anoxia. At sea level anything less than 19% oxygen content is dangerous.


Clearly you did NOT read the post you replied to. Otehrwise there is no way you could deny the non-uniform distribution without being non-rational.

As I said, a simple mixing experiment will clearly show your error.




I'm not suggesting it, it happens. Not Krakatoa, it was small large eruption. Mt. St. Helens size eruptions are fairly common and eruptions that raise ash to the lower stratosphere are very common. Right now there are 14 major eruptions in progress with two that are raising ash clouds over 30,000 feet. Mt Kilauea is releasing about 800 tonnes of sulfur dioxide every day.


So Krakatoa was "small"? And presumably the current eruptions are much bigger? That seems rather silly to say, given your OWN statements on the subject......

Volcanic activity is another "surface point source". while it rises up, it is not initially widely distributed, it must mix.

800 tonnes? There are power plants that burn coal at competitive rates to that. Coal being 100% carbon, every bit of it is combined with oxygen to form CO2. And the weight of produced CO2 is approximately 3X the weight of burned coal.




Every year volcanos put far more gasses and ash into the upper atmosphere than all the aircraft do in a decade or more. The output of many volcanic eruptions is measured in cubic miles not puny gallons.

Gallons? Gallons of WHAT?

There are 12,000 active commercial jet aircraft, according to figures I have seen.

Each one takes on fuel for a flight. Typically, each one makes several flights, or the equivalent in one long flight, per day.

The fuel resembles kerosene. Kerosene is a chain hydrocarbon with 12 to 15 carbon atoms. I would have to do a bunch of calculations which I do not presently have time for to get at the exact amount of carbon per gallon.

However, the weight of fuel would be about 90% carbon, given the relative weight of carbon and hydrogen. So each US ton of kerosene fuel is roughly 1800 lb of carbon. Burned, it will be about 5000 lb of CO2, since 2 oxygens are added per carbon, increasing the weight.

So if each of the 12,000 aircraft made only one flight, for which it took on and burned only one ton of fuel, per day (which is clearly an underestimation), the fleet would produce something like 63 million pounds of CO2 per day.

That is about 30,000 US tons, and we can be quite sure that the fuel usage figure of one ton per day per aircraft is so under-estimated as to be ridiculous. The true number is much greater than that.

I'll let you figure out the volume of that much CO2. You can do it for STP, or for ah higher altitude, such as 35,000 ft.

If you want, you can estimate the true usage of fuel, and the corresponding larger CO2 output.

It may help your understanding.

Evan
07-31-2008, 09:38 AM
A single volcanic eruption may release millions of tonnes of CO2 and sulfur dioxide in one day. There are 14 major eruptions taking place as of yesterday and many more at a low level. Just in British Columbia alone there are over 100 volcanoes, many of them active.

Volcanoes release over 130 million tonnes of CO2 per year into the atmosphere, much of it to the upper atmosphere.

See here. It may help your understanding.

http://volcanoes.usgs.gov/Hazards/What/VolGas/volgas.html

J Tiers
07-31-2008, 09:09 PM
A single volcanic eruption may release millions of tonnes of CO2 and sulfur dioxide in one day. There are 14 major eruptions taking place as of yesterday and many more at a low level. Just in British Columbia alone there are over 100 volcanoes, many of them active.

Volcanoes release over 130 million tonnes of CO2 per year into the atmosphere, much of it to the upper atmosphere.

See here. It may help your understanding.


You may have missed a small detail........

The figure I presented is, per added research at sciencedirect.com, about equal to the CO2 per day emitted by aircraft flying directly over china alone.

That small portion of the total airline emission amounts to 10 million tonnes (it was in metric tons) of CO2 per year.......

The US uses about 21 billion gallons of jet fuel per year, amounting to another roughly 27 million tons of CO2. Source Wikipedia, look up kerosene and jet fuel.

Other countries use jet fuel also*, and it would be very surprising if the worldwide total were not double the almost 40 million tons of CO2 emitted in the two countries so far mentioned. Call it 80 million tons, the figures are not accurate enough to get closer.

Now, your "puny gallons" are starting to look like a not-so brilliant assessment, eh? (no those words of yours are NOT "put in your mouth", look above, read 'em and weep)

We are up to about 2/3 of the number for all the volcanoes you can scrape up to add in.

In other words, the actual total emission when AIRCRAFT SOURCES USING JET FUEL are added in to your volcanoes is quite reasonably estimated as AT LEAST 150% of the the NATURAL total emission of the volcanoes alone.

Now, any effect which adds at least half again to a total is a significant effect.


Every year volcanos put far more gasses and ash into the upper atmosphere than all the aircraft do in a decade or more. The output of many volcanic eruptions is measured in cubic miles not puny gallons.

Excuse me, did I hear something about "puny gallons"? And decades?

It appears, USING YOUR OWN QUOTED NUMBERS FOR VOLCANOES that aircraft are quite competitive with volcanoes in the emission of CO2. The dust amounts, fortunately, are far lower. Aircraft reduced to dust in that quantity would be a real problem........:D

The wiki article mentioned above states airlines account for 11% of total US transportation sector greenhouse gas emissions. No reference for that one, but if true, definitely a significant contribution, and given the location of much of the emissions, definitely worth serious investigation.

* Lufthansa ALONE SAVED over 187,000 TONS of fuel last year, according to their own claims....... That is not what they USED, it is what they could SAVE by shaving a little here and a little there...... They claim a SAVING of about 600,000 tons of CO2 emissions in that time.

J Tiers
08-01-2008, 08:03 AM
I see I made a small error in calculation, due to the 4-banger calculator not accepting the last zero. Serves me right for not using scientific notation.

21 billion gallons of jet fuel, which is essentially kerosene, at about 400 gallons per ton, ACTUALLY is 52 million tons. Ten times what I originally calculated.

THAT GIVES ABOUT 135 MILLION TONS OF CO2.... ALREADY MORE THAN EVAN's QUOTED AMOUNT FOR VOLCANOES..... and some other countries use jet fuel also.....

Evan
08-01-2008, 10:16 AM
Your numbers are wrong by a very significant degree. According to the US Bureau of Transportation Statistics, the amount of aviation fuel, all types, consumed in 2007 by all US carriers, scheduled and unscheduled, national and international, was 19.7 billion gallons. That includes avgas as well as jet fuel and a large fraction of the jet fuel is burned at low altitude by regional carriers and rotorcraft.

http://www.bts.gov/programs/airline_information/

Also, there are 292 gallons of Jet A per ton.

[edit]

Allotting 1/4 of that to actual flight at high altitude (most fuel is burned at low altitude) that gives about 16 million tons burned at high altitude. Note also that the numbers for volcanos are averages. A single event such as the Mt. Pinatubo eruption lowered world temperature by an easily measurable .5C for over a year.

Evan
08-01-2008, 11:09 AM
Note also that I haven't actually mentioned how much CO2 volcanoes emit. The Kīlauea Volcano is measured as emitting about 9000 tonnes per day or 3.3 million tonnes per year. That rate is essentially constant.

http://www.agu.org/pubs/crossref/2002/2001JB000407.shtml

The emission rate for an active volcano is measured in the thousands of metric tonnes per day. Because of the rapid mixing of the low level atmosphere those emission will be distributed equally throughout the air column up to and including the altitudes jets fly at. Even with that sort of CO2 emission the overall effect of volcanic eruptions is to COOL the climate because of the overwhelming sunscreen effect of ash clouds. The exact same logic applies to Jet aircraft and the shadowing caused by contrail clouds. All major volcanic eruptions result in cooling, never warming.

Anything that blocks the solar input so outweighs the additional absorption of greenhouse gasses that no practical amount of GG emission can make up that difference. Keep in mind that greenhouse gasses are not 100% black body absorbers, they only absorb a fraction of the heat that is re emitted as long wave radiation. The absorption caused by high altitude deposition of CO2 might increase the outgoing absorption by a single percentage point or so but the blocking effect of contrail clouds is hugely greater since they will reflect nearly 100% of incoming energy during daylight hours.

They influence of clouds in general is markedly a cooling influence. They act as a climate moderator preventing extremes of temperature. Even at night the emission rate of longwave IR from the earth is perhaps only 1/1000 of the insolation rate during the day from the sun. When is the last time that you were able to warm your hands by holding them over the ground on a cool night? Obviously, the emission from the ground at night cannot come close to the energy accumulated during the day. So, even if a cloud was a perfect reflector on both top and bottom it will reflect away far more energy than it reflects back to earth. The amount of energy reflected by one cloud made by one jet on one day probably outweighs all the energy absorbed by all the CO2 emissions by all the jets on the same day.

A Terawatt is a LOT of energy and the solar flux at Earth is a gigawatt per square kilometer. A contrail that doesn't even spread but just hangs around for an hour could reflect as much as 100 gigawatts for every hour the jet is at altitude assuming it is flying 1000 kph and the contrail is 100 meters wide, very reasonable assumptions. That means a terawatt of reflected energy for a 10 hour flight from Europe during the day even if no major clouds are formed.

J Tiers
08-01-2008, 09:56 PM
Your numbers are wrong by a very significant degree. According to the US Bureau of Transportation Statistics, the amount of aviation fuel, all types, consumed in 2007 by all US carriers, scheduled and unscheduled, national and international, was 19.7 billion gallons. That includes avgas as well as jet fuel and a large fraction of the jet fuel is burned at low altitude by regional carriers and rotorcraft.

http://www.bts.gov/programs/airline_information/

Also, there are 292 gallons of Jet A per ton.


Sorry, you ain't exactly helping your cause..... with bad numbers.

Mine come from the US DOE

according to YOUR numbers, first reduce the total to 93.8% of the quoted number.

Now MULTIPLY it by 400/292= 1.36 since you corrected the gallons per ton to be heavier. I rounded it off up, from a wiki article which gave the density..... making my number smaller than it really is.

So using YOUR numbers, the total is STILL actually 136% of what I said it was...... but unfortunately your numbers are wrong. Airlines use some, and the military uses some also. I really don't care which type of aircraft it is (ok the military burns a little in trucks too, but trucks don't burn it by the tons per day each)

Avgas is completely insignificant. The totals are so small as to be unworthy of mention. refer to the link below to see that.

In any case.... according to the US government, in 2006, there were 57,840,000 gallons of "kerosene-type jet fuel" sold per day (54,849, in units of 1000 gallons). 2006 was the year I got the numbers from. In 2007 it was actually a little higher........

If you check, that number x 365 is 21 billion (2.1 x 10^10) gallons

http://tonto.eia.doe.gov/dnav/pet/pet_cons_prim_dcu_nus_a.htm

Yes it is "sold volume" but I don't believe this is the futures market, this is volume sold to users, who intend to use it. It's close enough to your numbers to be quite credible anyhow, adding in military volumes.

The points in THIS part of the argument is that

1) We are NOT dealing with "puny gallons" as you defiantly insisted

2) Even using YOUR numbers, of 130 million tons from volcanoes, it will NOT take any "decade" for the aircraft total to equal one year of volcanic activity.

And as for the low-level deposition, SURE..... why not? The more, the merrier. Your volcanoes are low level also, compared to 39,000 feet to 43,000 feet, which numbers come to mind from relatively recent longer distance flights.

If some aircraft of low capacity and smaller size fly at only 25,000 feet, it won't bother me a bit.

Evan
08-01-2008, 11:48 PM
ALL AIRCRAFT must taxi, take off and land as well as climb to and descend from altitude. In fact, only the long haul aircraft make it to the upper flight levels. Regional jets never fly that high and a passenger jet flying across the us may spend 20% of it's time below cruise altitude.

Jet fuel is sold for a lot more than fueling jets. It's widely used in temporary turbine power plants.


Sorry, you ain't exactly helping your cause..... with bad numbers.

Mine come from the US DOE

according to YOUR numbers, first reduce the total to 93.8% of the quoted number.

Now MULTIPLY it by 400/292= 1.36 since you corrected the gallons per ton to be heavier. I rounded it off up, from a wiki article which gave the density..... making my number smaller than it really is.

My numbers come from Exxon, the people that make it.

A tonne contains 264 US gallons of water. Jet A has a density of .775 to .840, average 807. 264/.807=327 gallons of Jet A per metric tonne. Convert to US ton gives 297 gallons per US ton, very slightly heavier than the given number and much less than yours.

http://vts.bc.ca/pics4/jetfuel.jpg

Avgas sales are 209 million gallons last year. It isn't used much for anything but aircraft.
http://tonto.eia.doe.gov/dnav/pet/pet_cons_prim_dcu_nus_a.htm

J Tiers
08-02-2008, 09:09 AM
My numbers come from Exxon, the people that make it.


That's nice, my numbers come from the agency that keeps track of all of it, exxon's plus any other as well.

The numbers are close enough (19.7 vs 21) that it there is no major issue.




A tonne contains 264 US gallons of water. Jet A has a density of .775 to .840, average 807. 264/.807=327 gallons of Jet A per metric tonne. Convert to US ton gives 297 gallons per US ton, very slightly heavier than the given number and much less than yours.


right..... which give, as I mentioned, a very substantial BOOST in the total tons of CO2 produced, as fewer gallons per ton mean a given number of gallons are MORE tons.... So even if I use YOUR numbers, the total EMISSIONS GO UP.

Thanks for making more points in favor of my argument :D



Avgas sales are 209 million gallons last year. It isn't used much for anything but aircraft.


So bringing it up isn't exactly changing the totals by a significant amount, is it?....... 209 million is pretty close to 1% of 21 billion. THAT is truly "puny gallons". And the 21 billion is only kerosene type jet fuel anyway, no avgas.


ALL AIRCRAFT must taxi, take off and land as well as climb to and descend from altitude.

Perfectly true.

And not exceptionally important.

While a jet is spectacularly inefficient when taxiing or sitting and waiting in line, the idea is supposed to be traveling..... so the bulk of the time is actually in the air.

Quite a substantial amount of fuel is used in takeoff and climb-out, naturally as well. That occurs at various altitudes between ground and cruise altitude, so it is to some extent averaged, although a bit weighted towards lower altitudes due to takeoff.

Fact remains that even a shorter-haul jet spends as much time as possible actually flying (that pays the bills), at altitudes which are at least comparable to common mountains. And, the short haul jets are smaller , burning less fuel overall per flight, although often also older and less efficient.

I believe the point is made....
It is inescapable that a very large amount of CO2 is deposited directly in the atmosphere at higher altitudes, by aircraft.

The amount is certainly quite comparable to the annual emissions from the largest natural point sources, and is IN ADDITION TO those natural sources, which are in any case part of the long-established "balance of nature", and are to that extent "discountable". They extend back to times when the earth was NOT rapidly warming, and so by themselves are not apparently disturbing the balance.

The large ADDED amount of nearly continuous emission of pure greenhouse gas directly at high altitudes by aircraft has no precedent.

Evan
08-02-2008, 09:40 AM
You are avoiding the point. It isn't large compared to the energy balance change caused by the contrail clouds. They truly have no precedent unlike high level injections of green house gasses.

While it isn't confirmed what the net effect of contrail clouds is there is no doubt that they reflect a great deal of energy back to space. For that to be counter balanced or even exceeded requires a mechanism not yet described.

zukIzzy
08-03-2008, 11:31 PM
You 2 really enjoy the argument don't you?:D I like all the info coming from both sides. I have to give Evan the edge right now but I am sure J Teirs has got a hook or 2 left yet.. the constant jabs from Evan are stifling though.

Wayne

gramps
08-04-2008, 01:21 PM
I just came across this and would like to see some comments.
Is this for real? If so it shure sounds good.


http://web.mit.edu/newsoffice/2008/oxygen-0731.html

dp
08-04-2008, 03:02 PM
I just came across this and would like to see some comments.
Is this for real? If so it shure sounds good.


http://web.mit.edu/newsoffice/2008/oxygen-0731.html

It's going to take a hell of a lot of square meters of solar cells to replace the 200 amp circuit in my house. Even if it replaces only a few of those amps and even that would be difficult as Seattle is not a solar-friendly town. That is economy I can't afford.

Evan
08-04-2008, 04:08 PM
From that story:



Requiring nothing but abundant, non-toxic natural materials, this discovery could unlock the most potent, carbon-free energy source of all: the sun.
...
The new catalyst consists of cobalt metal, phosphate and an electrode, placed in water.


Cobalt is very toxic and is responsible for a condition called "hard metal disease" which afflicts people that inhale the dust from grinding carbide tooling among other things. It also isn't particularly abundant with the current price at $38.50 per pound and the price last March at $50 per lb. The price is expected to go up rapidly as demand increases. World production was only about 60,000 tonnes, minuscule compared to most metals.

Note also that this isn't "free energy". It still takes 237 kilojoules of energy to change one mole of water to 1 mole of hydrogen and .5 moles of oxygen.

J Tiers
08-04-2008, 07:48 PM
You 2 really enjoy the argument don't you?:D I like all the info coming from both sides. I have to give Evan the edge right now but I am sure J Teirs has got a hook or 2 left yet.. the constant jabs from Evan are stifling though.

Wayne

Nope, I'm tired of it, I already demolished some key statements by Evan, I am now bored.

uute
08-04-2008, 11:27 PM
Here is a site with info on state & federal incentives for renewables:

http://www.dsireusa.org/

JRouche, You'll typically stay connected to the grid, so you'll have full capacity available all the time, and no batteries to contend with. In many states, every kw you generate will offset one on your bill, no matter when it is generated or when you use an offsetting kw. (net metering).

YOD said:>>if the wars we fight are for oil, why the hell are we paying $4+ for gas and $5+ for diesel? I don't get it.

Kinda like when you fight ovear a girl, ya get a black eye - but often not the girl!! ;D

pcarpenter: The main thrust behind Boone Picken's plan is to make electricity from wind instead of natural gas so we can use the Nat Gas for transpertation instead of oil. It is an idea he has advocated for years, just much more vocally lately.

uute

zukIzzy
08-05-2008, 12:00 PM
Nope, I'm tired of it, I already demolished some key statements by Evan, I am now bored.

Oh I am sorry to see you throw in the towel. The banter was fun to watch. Demolished is subjective I guess. I thought both points were well represented and saw no clear winner.

Wayne

J Tiers
08-05-2008, 11:44 PM
Oh I am sorry to see you throw in the towel. The banter was fun to watch. Demolished is subjective I guess. I thought both points were well represented and saw no clear winner.

Wayne

Nope, took my towel along with me.........

Unlike SOME people, I don't have to have the last word to feel justified. If I know the facts have been bought out, and that they are in direct conflict with the statements of an "opponent" in an argument (as in the present case), I don't care if the "opponent" agrees he is wrong. I know what's what.

I want an opponent to agree he is wrong, if he is, but I've got old enough that my wants don't hurt me so badly.............