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Building a grid tied system today... a hybrid system in 5 years?

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  • Building a grid tied system today... a hybrid system in 5 years?

    I need some advice on putting together the optimal system to future proof a brand new solar installation. I'm looking to be in my Southern California Edison house for a long long time (30+ years?) I'm having trouble picking between inverters, what to invest now vs. the future, and looking ahead to whether I want an AC or DC coupled battery system. Part of how I want to design this depends on what technology/price points are anticipated in the 5-10 year mark.

    Install now: I've sized the system for about 7000 kWh of annual generation. I'm leaning on Panasonic panels as they are in the top tier for degradation over time and temperature. Not sure about what type of inverter though... (Enphase IQ... 8?, EnergyEdge? Schindler XW?) I'd like to get in this year before the federal rebate gets reduced.

    5-10 years from now: the grandfathered TOU plan I'm on now expires and I will be pushed into a plan that rewards a battery. While I'm brand agnostic, I would like the battery to operate in the event the grid goes down if the price is right.

    5-10 years from now: I buy an electric car. Expand the solar array to accommodate the extra usage.

  • #2
    Hybrid systems require a battery, they cannot be used without one. I suggest a simple GT system now, and plan to buy all new for the switch over.
    Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister

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    • #3
      Originally posted by Mike90250 View Post
      Hybrid systems require a battery, they cannot be used without one. I suggest a simple GT system now, and plan to buy all new for the switch over.
      The Outback Skybox is one Hybrid Inverter that can run without batteries, however It is limited to 5000 Watts. I believe the SolarEdge StoreEdge can also run without batteries. It is DC Coupled and only works with 400v LG Chem batteries so your expansion is limited to LG Chem. Currently LG CHem is limited on battery capacity. Mikes suggestion of a simple grid tie. system may be the best call for now. I had a similar dilemma in 2017 and that is what I chose to do.

      There are a lot of new players coming on to the market with AC coupled battery/Inverters so you will have more choices in the future. The California Self Generation Incentive Program has been extended to 2025 and that will continue to give you better options. Most of the AC coupled systems will work with any old inverter but since you are in California your City or County building authority will require NEC 2014 rapid shutdown. An even more stringent NEC 2017, if adopted by your building department, may limit you to Enphase of Solaredge. I did have a reservation on a Tesla Powerwall but got tired of waiting and just recently installed a Outback Skybox. I already had the batteries so that made it somewhat competitive with the Powerwall plus it allowed more flexible expansion path.
      Last edited by Ampster; 03-13-2019, 09:03 PM.
      9 kW solar, 42kWh LFP storage. EV owner since 2012

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      • #4
        Agree w/Mike on that one. Also, whenever you get PV/battery/EV, you will have a choice of T.O.U. tariffs available, some more/less favorable to you as f(your situation) re: GT/Hybrid/EV/no EV. Get informed about current and possible future options and how things might change.

        Some possible considerations:
        - Tax credits get reduced as of 01/01/2020, changing the assumptions regarding cost effective.
        - PTO rules from POCO may be more hassle/PITA for system expansion(s). Also, and mabe not so good, POCO interface rules for new battery systems may (or may not) change before you get one.
        - GT now for max. PV fed. tax credit Take your best shot at future annual usage w/wo EV(s), get PV sized as per your best shot at that future average annual usage w/wo EV(s). Problem there is folks usually don't know/don't want to learn about cost effective sizing and how to analyze consequences of under/over sizing.
        - Add batteries as that tech. matures and price comes down (?), keeping risks associated w/waiting in mind.

        The more informed you are, the higher the probability you'll make better choices.

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        • #5
          Originally posted by J.P.M. View Post
          ............
          - PTO rules from POCO may be more hassle/PITA for system expansion(s). Also, and mabe not so good, POCO interface rules for new battery systems may (or may not) change before you get one.
          .........
          I seem to be a lone voice on this subject, As far as I can tell, there is no California law that says you have to get permission from your utility to install a battery backed system behind the meter. I have looked but found no such law to that prohibits that. Clearly, you would need to get a building permit. To do that, the battery inverter would have to comply with the latest Underwriters Lab and NEC requirements. This is the same procedure that you would have to follow if you installed a generator with a UL approved transfer switch to back up your home.

          However, if you wanted to get the California Self Generation Incentive Program rebate the only way to apply for SGIP funds is through your power company. Also, the California Public Utilities Commission has just adopted rules that would allow you to get credits for storage sent back to the grid. They have also streamlined the rules to do so. My point is that I do not believe there is much downside risk in the future in California for installing batteries behind the meter because when used properly they can be beneficial to the grid.
          Last edited by Ampster; 03-13-2019, 12:35 PM.
          9 kW solar, 42kWh LFP storage. EV owner since 2012

          Comment


          • #6
            Originally posted by Ampster View Post
            I seem to be a lone voice on this subject, As far as I can tell, there is no California law that says you have to get permission from your utility to install a battery backed system behind the meter. I have looked but found no such law to that prohibits that. Clearly, you would need to get a building permit. To do that, the battery inverter would have to comply with the latest Underwriters Lab and NEC requirements. This is the same procedure that you would have to follow if you installed a generator with a UL approved transfer switch to back up your home.

            However, if you wanted to get the California Self Generation Incentive Program rebate the only way to apply for SGIP funds is through your power company. Also, the California Public Utilities Commission has just adopted rules that would allow you to get credits for storage sent back to the grid. They have also streamlined the rules to do so. My point is that I do not believe there is much downside risk in the future in California for installing batteries behind the meter because when used properly they can be beneficial to the grid.
            I believe I agree with most of what you believe about CA law with respect to energy storage systems. I don't think CA law addresses limits of residential energy storage systems beyond what you describe. At least not yet.

            But, I'd add that some CA POCOs (like mine) get kind of porky about the rules of on site electrical energy storage and what they (the POCOs by their tariff rules) can do to keep or limit some users from using storage capacity to, for example, simply shift POCO draw to super off peak times. That would be a scenario such as where a residential energy storage unit is in place w/out PV and used pretty much for the sole purpose of, say, sizing a storage system perhaps much larger than the paltry 8 - 13 kWh or so toys usually discussed these days - say up to the size of a daily usage profile for a residence or greater, charging that larger storage system during super off peak times, and then running off the stored electricity until the next super off peak rate time.

            I kind of suspect the POCOs don't care much for that idea of what they may consider unfair gaming of the system by residential users, and will do what they can to make it difficult for residential users to pull off such things if it impacts grid safety, or POCO profitability, or both.

            (See: www.sdge.com/residential/solar/solar-batteries-and-energy-storage )

            There are lots of things CA, or any law for that matter, simply doesn't address. But because the law does not address something doesn't mean that something is disallowed - such as where a business promulgates rules and policies to regulate the use of their product, at least not until some practice or policy gets challenged in court and adjudicated.

            Also, you can probably bet your ass the CA POCOs have either done what they can to prestacked the CPUC policy and regulation deck, or users such as you, me or others are ignorant of such CPUC rulings or their effect(s). POCOs are not stupid.

            I'd add, whatever POCO policy or legislated limits may or may not be in placed at this time with respect to residential energy storage, or anything else for that matter, and this may be a no**** no brainer, but I'd suggest both will change as events develop.
            Last edited by J.P.M.; 03-13-2019, 11:49 PM.

            Comment


            • #7
              Originally posted by Ampster View Post

              The Outback Skybox is the one Hybrid Inverter that can run without batteries, however It is limited to 5000 Watts. I believe the SolarEdge StoreEdge can also run without batteries. It is DC Coupled and only works with 400v LG Chem batteries so your expansion is limited to LG Chem. Currently LG CHem is limited on battery capacity.
              The StoreEdge deffinitly can work without the battery, and though the LG Chem RESU10H is limited currently, you can connect up to two of them on a single StorEdge inverter.
              Also SolarEdge has a trade in upgrade program from the standard SE7600 to the StorEdge version.




              OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

              Comment


              • #8
                Originally posted by J.P.M. View Post

                I believe I agree with most of what you believe about CA law with respect to energy storage systems. I don't think CA law addresses limits of residential energy storage systems beyond what you describe. At least not yet.
                Of course, I have no way to predict the future. However, I believe the right to generate power is fundamental unless it violates other codes related to health and safety.
                But, I'd add that some CA POCOs (like mine) get kind of porky about the rules of on site electrical energy storage and what they (the POCOs by their tariff rules) can do to keep or limit some users from using storage capacity to, for example, simply shift POCO draw to super off peak times. That would be a scenario such as where a residential energy storage unit is in place w/out PV and used pretty much for the sole purpose of, say, sizing a storage system perhaps much larger than the paltry 8 - 13 kWh or so toys usually discussed these days - say up to the size of a daily usage profile for a residence or greater, charging that larger storage system during super off peak times, and then running off the stored electricity until the next super off peak rate time.
                Porky? They have the right act any way they see fit. What "rules of on site electrical energy storage" are you talking about? Yes if one applied to them for SGIP funds then one has to accept what ever rules go with that agreement. That is called a contract. Describe how the POCO could unilaterally tell me I cannot build a great big a energy storage device as long as it is permitted by the building code. There may be a limit but currently I park two cars with a total of 130 kWhrs in my garage. There is no law about that.

                I kind of suspect the POCOs don't care much for that idea of what they may consider unfair gaming of the system by residential users, and will do what they can to make it difficult for residential users to pull off such things if it impacts grid safety, or POCO profitability, or both.

                (See: www.sdge.com/residential/solar/solar-batteries- and-energy-storage for an example.)
                I absolutely agree they don't care for the idea. It is called load departure and it is one of the things that could cause them to go into a death spiral if their rates are so high that alternative forms of generation that are cheaper cause load departure . Again, I am not talking about anything that would impact grid safety. The anti islanding function is accomplished by an UL approved automatic transfer switch.
                BTW the URL didn't work but even if it did I bet it uses language that is ambiguous. At least SCE and PG&E have written similar stuff. I read a specific example about a generator and all they said was to let them know. Next time I see a local lineman I will give him a shout out. I was actually talking to a lineman last week as he was hooking up my new main service panel and we talked about my backup inverter that was powering my house while service was down. All he cared about was no backfeed (anti islanding).
                There are lots of things CA, or any law for that matter, simply doesn't address. But because the law does not address something doesn't mean that something is disallowed - such as where a business promulgates rules and policies to regulate the use of their product, at least not until some practice or policy gets challenged in court and adjudicated.
                Give me an example where someone has been successful doing that. I understand rules as part of contracts or rules from an HOA that one accepts by reason of being bound by the CC&Rs. If the law does not address something, then it is not illegal. This is still a country that abides by the rule of law.

                Also, you can probably bet your ass the CA POCOs have either done what they can to prestacked the CPUC policy and regulation deck, or users such as you, me or others are ignorant of such CPUC rulings or their effect(s). POCOs are not stupid.

                I'd add, whatever POCO policy or legislated limits may or may not be in placed at this time with respect to residential energy storage, or anything else for that matter, and this may be a no**** no brainer, but I'd suggest both will change as events develop.
                Change is inevitable. Yes they are not stupid. I am also not so stupid to think some POCO or the CPUC or my liberal legislators will take away my rights. As to the relevance to the OP, I still do not think there is any downside risk of your right to install batteries being taken away in the future, particularly with the direction California is headed with its Renewable Portfolio Standards.
                Last edited by Ampster; 03-13-2019, 05:03 PM.
                9 kW solar, 42kWh LFP storage. EV owner since 2012

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                • #9
                  You can also look into the Pika Energy system, the Hybrid inverter can be first installed without the battery, and their battery installed later on

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                  • #10
                    Just wanted to thank you all for the input. I think I was under the impression that the technology here was more mature than it is. The consensus seems to be to wait a couple of years for improvements in technology and for the prices to drop (hopefully faster than the rebates drop). I'll ask the solar installer for a StorEdge system estimate w/o the battery... but I'm guessing this is going to be a bit more than I should/want to spend at this time.

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                    • #11
                      Originally posted by jhuang0 View Post
                      Just wanted to thank you all for the input. I think I was under the impression that the technology here was more mature than it is. The consensus seems to be to wait a couple of years for improvements in technology and for the prices to drop (hopefully faster than the rebates drop). I'll ask the solar installer for a StorEdge system estimate w/o the battery... but I'm guessing this is going to be a bit more than I should/want to spend at this time.
                      PV technology is pretty mature - to the point panels and a lot of associated equipment are now virtually a commodity. I'd consider getting the PV now if you can justify the economics to yourself, and bet on energy storage being able to accomodate existing and future systems (such as yours perhaps) once that sector gets to the same marketability that PV has now.

                      In the opinion of a good portion of knowledgeable folks, here and elsewhere, electrical storage systems probably aren't quite ready for prime time just yet. The POCOs will also have some say in the deployment of distributed (read: residential) storage. That battle will likely be similar to but I'd guess larger than the one just now concluding over NEM. Sit on the sidelines and watch that one to get the lay of the land before getting residential batteries. If nothing else, the prices will probably come down.

                      Good luck.
                      Last edited by J.P.M.; 03-14-2019, 09:15 PM. Reason: Grammer.

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