Announcement

Collapse
No announcement yet.

O/T: My state of California has gone looney tunes with power usage restrictions.

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #61
    Originally posted by Paul Alciatore View Post
    . . .I must suspect that those "smart" meters would have some kind of protection to prevent this; in other words, a DISCONNECT.
    . . .There is another problem here: synchronization. Those "smart" meters also must be providing a way to synchronize the solar power generated with the 60 or 50 Hertz frequency of the grid.
    I was told the micro-inverters take care of both synchronization and shutdown. It would be interesting to know whether the meter has provisions as well.

    Southwest Utah

    Comment


    • #62
      Originally posted by Paul Alciatore View Post
      But J Tiers was not talking about normal, day-to-day operation of a solar panel. He WAS talking about a power outage situation when the grid power is absent due to some kind of emergency. In that case, your solar panels would be trying to fill an empty Atlantic Ocean one drop at a time.

      That situation would have the same safety concerns that I brought up in my earlier post. The power company linemen would need to work on the bad lines and they would want them to be dead, not live. I can not believe that the power companies would want their faulty grid being back-fed under those conditions. And I must suspect that those "smart" meters would have some kind of protection to prevent this; in other words, a DISCONNECT.

      Under normal circumstances the "smart" meter would measure the power transmitted both ways and you would get 100% use of the electricity generated by your roof top solar panels. But under emergency conditions there must be some kind of disconnect for safety reasons. So, in short, he is not providing free electricity to the power company under any conditions. And his home should have full use of the power generated in an emergency.

      There is another problem here: synchronization. Those "smart" meters also must be providing a way to synchronize the solar power generated with the 60 or 50 Hertz frequency of the grid. The grid provides the reference frequency for that and the solar system at the individual home must synchronize with it in order to feed power back into the grid. But if the grid power is absent, then what does the local, solar system in one home do? And what if there are two or more such homes that are connected together by a small, local part of the grid. Surely one or several such solar systems would not keep in sync with the grid power when that is no longer present. And then, when the power company is ready to restore that part of the grid to their power, just how is the synchronization accomplished. If that local pocket of solar power is out of phase with the grid power, there is going to be one heck of a spark when the two are connected. And if you are lucky, only a breaker trips. If you are less lucky, one of the grid's lines goes up in smoke and the repair just got a lot longer.

      Yet another problem would the broken lines that are laying on the ground/streets. If they are being back-fed then they are a danger not just to the power company's linemen, but also to anyone who may come into contact with them. The power company has breakers that will normally open when a line is grounded and even when that does not happen, a lineman can open the feed to that line. But what about the other side of that broken line. To make it safe they would have to knock on every door to get the solar power turned off.

      There are just so many reasons why power can not be back-fed into the grid under emergency conditions. I simply can not believe that the power companies would allow this in any area.

      If this is not how it works, I would appreciate an explanation from someone who really knows.

      PS: I have lived much of my life in hurricane prone areas and have seen and lived in massive power failures. I have seen homes without power for a week or more due to massive numbers of problems with the grid. And I have seen more than a few live lines laying on the street. To put it in the vernacular, "**** does happen!"




      Ok, a quick explanation on the things you brought up.

      First, grid tie inverters must disconnect from the grid within milliseconds if the grid goes down, the voltage exceed a tolerance either way, or the frequency exceeds a tolerance either way. So there is no danger of a grid tie solar backfeeding the grid during a outage. Related, the power company approves the equipment to be used before they will set a net reading meter (not the same as the average smart meter). The inverters have to be UL listed or the power company won't approve them. Then the whole installation has to be inspected before the power company will set that net reading meter.

      Synchronization to the grid frequency is a function of the grid tie inverter, not the meter. When the grid is down, its meanless anyways because the inverter shuts down anyways.

      Back feeding the grid and synchronization are only relevant with grid tie inverters/solar setups. Off grid systems/inverters NEVER feed the grid but some (hybrid) can consume power from the grid under certain circumstances, if so desired, its a parameter choice. Off grid systems normally have batteries used to store excess daytime production which supply the power during the night time or when there is real poor sunlight. Grid tie systems do not use batteries.

      JTiers was talking about both normal operation and also when the grid is down, he talked of both cases. As detailed above, a grid tie system never back feeds the grid during a outage, it simply shuts down.

      Oh yea, its standard procedure for power companies to install grounding cables/clamps on de-energized lines before they work on them. Its a safety thing just in case someone does back feed the lines with their generator or if another crew accidently energizes that line they are working on. In the case of a line down in the street, they may move that line with a long insulated fiberglass pole while it is live but then will de-energize it before going further. and install safety grounds. Power companies are very strict about that sort of thing, they have to be, they have elaborate safety procedures.

      Hopefully this clears up a few things for you. If not or I missed something, ask away.
      Last edited by Sparky_NY; 07-30-2021, 08:59 PM.

      Comment


      • #63
        Originally posted by chipmaker4130 View Post

        I was told the micro-inverters take care of both synchronization and shutdown. It would be interesting to know whether the meter has provisions as well.
        Yes, the inverter, either micro type or full size handle the frequency synchronization, never the meter. The meter simply measures power in each direction from the grid for net metering purposes. I have heard that some smart meters do have remote disconnecting capability but have never confirmed that, it would be mostly for ease of turning off non-payers remotely.

        Comment


        • #64
          What a bunch of nut jobs. I can't imagine they'd like home machine shops with phase converters and large lathes, etc. F em.
          21" Royersford Excelsior CamelBack Drillpress Restoration
          1943 Sidney 16x54 Lathe Restoration

          Comment


          • #65
            Originally posted by Paul Alciatore View Post
            ..............................

            There are just so many reasons why power can not be back-fed into the grid under emergency conditions. I simply can not believe that the power companies would allow this in any area.

            If this is not how it works, I would appreciate an explanation from someone who really knows.

            PS: I have lived much of my life in hurricane prone areas and have seen and lived in massive power failures. I have seen homes without power for a week or more due to massive numbers of problems with the grid. And I have seen more than a few live lines laying on the street. To put it in the vernacular, "**** does happen!"
            I think you are deliberately misunderstanding. Why insist that this means powering the grid? It does not.

            UL 1741 has set requirements on voltage and frequency, such that for a HOME inverter that is grid tied, it must "stop feeding the grid" within X number of cycles if either voltage or frequency exceeds limits, high, or low.

            The parameters used are set by the power company tariffs, which I have someplace along with 1741. (The requirements for an "intermediate" source, in the hundreds of kW area, are different, and include "ride-through" conditions for which the source "must not" disconnect for a set time in seconds, as well as wider limits for which it must disconnect.)

            The requirement is NOT that "it shall turn off and become inoperative". It can do whatever, so long as it does not export power, as far as the powerco is concerned.

            In fact, most that I have worked with simply open a contactor and then go into a standby mode, waiting for the grid to remain stable within the parameters for a set period, which IIRC is 5 minutes.

            There really is NO reason nor requirement that means the inverter cannot power your own house, by simply disconnecting from your "drop", your connection to the grid. You would become isolated, and no danger to anyone working on the grid.

            This is already done, but often is via a manual cutover switch. Some generators, such as at least certain "Generac" models, do this automatically. A grid tie inverter could do it also. And some are beginning to. But it has taken many years to get there for consumer inverters.

            We used a Basler device which did the monitoring, and needed to be "programmed" for the needed parameters. It cost nearly what a grid-tie inverter costs, just by itself. That function is already inside the grid-tie inverter, per UL1741.

            I could be wrong, but I believe there are few if any turnkey consumer systems that will also cut over to battery if/when the solar cannot supply the load and power is out. Nor that will charge batteries with whatever is excess beyond the current load. That last could be a good thing, but obviously adds complication.

            The ideal inverter that would switch to powering the house disconnected from the grid is not without technical issues.

            The inverter would need to supply it's own 60 Hz reference, because a UL 1741 inverter synchs to the grid, and follows all frequency variations It has an internal reference only to detect frequency deviations outside of limits. To supply power to the home, it would need to switch to an internal source of frequency. And switch away from that again, to reconnect to the grid.

            Another reason why a simple grid-tie cannot now directly power your home is the basic design. The grid is an "infinite sink". The UL1741 inverter therefore pays no attention to voltage, and simply dumps current into the grid connection. The grid is very low impedance (in theory), and simply accepts the current. Trying to control voltage would be to fight the entire grid. When powering your house, it would obviously have to maintain a stable voltage.

            So the cutover would involve opening the grid connection, connecting a frequency reference, connecting a voltage control, and reconnecting to the house alone. None of that is difficult (in theory) for a microprocessor controlled unit.

            It is not difficult to do with two separate inverters, either. But one that does both, without duplication, is harder.

            The difficulty would be getting the system through UL, which would have to approve both hardware and software. That involves a very expensive and involved testing and line by line code tracing process prior to approval. Once approved, the same process for the slightest change. UL has processes for this, but it can be a huge hassle.

            So, few have wanted to go through that. There HAVE been such inverters, UL recognized, for some years, but they tend to be in the several tens of kW, and higher, and priced at several tens of kilodollars as well. If they are now coming down in price, that would be a good thing. But NOT if through UL china.







            2730

            Keep eye on ball.
            Hashim Khan

            Everything not impossible is compulsory

            Comment


            • #66
              This might be of interest to those that don't have a solar setup but are interested in the subject. Its a screenshot of the monitoring software for my system taken this morning. Lot of realtime data displayed and it also logs that data into a spreadsheet file every 5 minutes for later review. You can log at 1, 5 or 10 minute intervals, I use 5 minute. The screen data is refreshed 2X a second. Loads were light when the screenshot was taken, the AC was not running. With the AC running the inverter load percentage runs about 55% usually.

              Click on the image for a larger easier to read version.
              Click image for larger version  Name:	Screenshot from 2021-07-30 14-03-41.png Views:	0 Size:	268.0 KB ID:	1954030
              Last edited by Sparky_NY; 07-30-2021, 09:12 PM.

              Comment


              • #67
                Originally posted by The Metal Butcher View Post
                What a bunch of nut jobs. I can't imagine they'd like home machine shops with phase converters and large lathes, etc. F em.
                ?????????

                I don't have phase converters, and my lathe is a simple 12X36, but I have a number of friends with both of those. And CNC mills on converters.

                Funny, those of us who actually live in California (not all, but most) like it here very well.

                Of course, there's the problem of insane housing prices. Some cope with that by demanding (and getting) insane salaries.

                I'm here because I came before California became so very popular and could afford to buy a house. My son and his wife bought ten years ago, spending 20X the price I paid. But he rakes it in as a high-tech systems admin.

                -js
                There are no stupid questions. But there are lots of stupid answers. This is the internet.

                Location: SF Bay Area

                Comment


                • #68
                  Originally posted by J Tiers View Post
                  I could be wrong, but I believe there are few if any turnkey consumer systems that will also cut over to battery if/when the solar cannot supply the load and power is out. Nor that will charge batteries with whatever is excess beyond the current load. That last could be a good thing, but obviously adds complication.
                  Yup, you are wrong. My inverter does all those things as do several on the market. I posted a screenshot from this morning that shows it powering the load AND charging the batteries at the same time. It can also share load between grid/solar/batteries in any combination/priority you specify in the setup. Many inexpensive models on the market do these things and much more.

                  You can also parallel up to 6 of them for 30KW output OR configure them to provide 3phase power if so desired as well.
                  Last edited by Sparky_NY; 07-30-2021, 09:35 PM.

                  Comment


                  • #69
                    There's a saying: "As California goes, so goes the nation."

                    Say what you will about California, they're just the first to anticipate upcoming problems. In the late 1980's I ordered some tooling from a dealer in South Elmonte. I went to pick it up while I was there attending the WESTEC machinery show. The tooling was totally rusty. The company left their bay doors open during business hours. The rust was what the LA air did to exposed bare metal. 30 years later things are much better in spike of complaints about regulations..

                    Comment


                    • #70
                      it's the best and the worst state in the nation... it's the best location I mean it's got everything,,, but too many people and too many rules and regs...

                      if the population in the US was like 50 mill --- id have moved to cali a long time ago

                      Comment


                      • #71
                        Originally posted by Sparky_NY View Post

                        Yup, you are wrong. My inverter does all those things as do several on the market. I posted a screenshot from this morning that shows it powering the load AND charging the batteries at the same time. It can also share load between grid/solar/batteries in any combination/priority you specify in the setup. Many inexpensive models on the market do these things and much more.

                        You can also parallel up to 6 of them for 30KW output OR configure them to provide 3phase power if so desired as well.
                        I have not been investigating these for a few years, and back when I inquired, I got a lot of "you can't do that" responses. Obviously wrong, then and now, but the prevailing view at least in the customer contact areas of several inverter companies than.

                        I am happy to be wrong, since it makes a LOT of sense.

                        Now I wonder why folks were not being offered that choice when they bought a grid tie system? Might have been a condition of the grant, or something else, or just because that installer didn't do a brand that had the feature.

                        However, it is unlikely that the other poster has such a newer inverter if he has had the system for a number of years.

                        Mine is stand-alone solar charging and inverter output, as is my off-grid friend. I have little to no interest in grid-tie at the moment.


                        Partly due to cost and duplication, partly due to this state potentially rescinding the law requiring the powerco to accept grid-tie. "We" in MO hate greenies, love coal, are #1 or 2 for new covid cases, and know solar panels are a hoax that doesn't work. Only a matter of time.
                        Last edited by J Tiers; 07-31-2021, 11:08 PM.
                        2730

                        Keep eye on ball.
                        Hashim Khan

                        Everything not impossible is compulsory

                        Comment


                        • #72
                          Originally posted by loose nut View Post

                          Is it actually possible to fit a solar panel up there???
                          Up there? Meaning the roof or latitude?

                          Your question is at best ambuguis,

                          I live lower than you in regaurd to Latitude.

                          So it must mean up there in what? My roof? Hell know I didnt go up there, too dangerous for me "_

                          JR

                          I think there are 26 380vdc panels up there??? My numbers are off, no biggy JR

                          Comment

                          Working...
                          X