Time to Consider Solar Net Metering Alternatives: Storage

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feature-0-1382362726113.jpg The media has recently been full of stories about electric utilities being nervous and down right reactionary to adding solar (and wind) on the electric grid. On October 15th, The Huffington Post’s story on the Hawaii Electric Company (HECO) reported, “hundreds of Oahu customers have gotten burned in their transition to solar. They have gotten caught in limbo since September 6 when HECO changed the rules for connecting solar systems.”

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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage

    An interesting look at how industry should think of PV systems, how people with PV arrays should use them and that pure grid tie should NOT be used: Batteries should be used all the time for dedicated circuits!
     
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  • jaggedben
    jaggedben Solar Expert Posts: 230 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    westbranch wrote: »
    An interesting look at how industry should think of PV systems, how people with PV arrays should use them and that pure grid tie should NOT be used: Batteries should be used all the time for dedicated circuits!

    Well...no. That would be needlessly expensive and impractical for many people who are not knowledgeable about batteries. It would probably work decently in many institutional and commercial applications like the author mentions in his article, and generally work badly for most residential applications (excepting those lived in by the kind of DYI tinkerer types who frequent this forum, which is a very small minority). There are a lot of options between off-grid systems, UPS-like applications, and grid level storage. There's no need to badmouth any of them in favor of others.

    It's a shame that in the US (unlike in Germany, notably), it seems likely that the political system will allow utilities to shut down the expansion of grid-tied solar way before there is any technical or financial justification for it on a macro level.

    The author is trying to create demand for the particular business segment he is in, which is all well and good, and his analysis will be correct for some potential clients, but would not be for the majority if policy were to be based on societal level goals (e.g. energy independence, carbon emission reduction), rather than the financial interests of utilities. Hawaii, of course, is really a special case because their grids are so small. So some of his comments may apply well there and not on the mainland.
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    jaggedben wrote: »
    Well...no. That would be needlessly expensive and impractical for many people who are not knowledgeable about batteries.

    Whether it is practical or not does not depend on the people being knowledgeable about batteries. Battery maintenance is simple and can be done by anyone without any special knowledge, especially if the system is set up correctly.

    For some people energy independence on individual level is worth much more than energy independence on "societal level". For me, for example, energy independce on "societal level" is total non-sense invented by politicians to get elected.
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    Whether it is practical or not does not depend on the people being knowledgeable about batteries. Battery maintenance is simple and can be done by anyone without any special knowledge, especially if the system is set up correctly.

    Aye, but there's the rub. Battery maintenance is simple once you understand it, but the vast majority of people don't, and furthermore, they don't have any interest in understanding or dealing with it at all it.
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    ggunn wrote: »
    Aye, but there's the rub. Battery maintenance is simple once you understand it, but the vast majority of people don't, and furthermore, they don't have any interest in understanding or dealing with it at all it.

    If I would sell my house to a person who do not know anything about batteries, I would tell - every three months, open caps on few cells and look how much water is there. If it is below certain level, pour this amount of water into every cell. After that, if you see some cells have less water than others, add a little bit to them. I don't think it requires any understanding, or desire to understand.

    If I had AGMs, even watering wouldn't be needed.
  • jaggedben
    jaggedben Solar Expert Posts: 230 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    If I would sell my house to a person who do not know anything about batteries, I would tell - every three months, open caps on few cells and look how much water is there. If it is below certain level, pour this amount of water into every cell. After that, if you see some cells have less water than others, add a little bit to them. I don't think it requires any understanding, or desire to understand.

    If I had AGMs, even watering wouldn't be needed.

    The average person you sell your house to will smile, nod, say "let me take notes! I'm so excited about this!", leave their notes by the batteries .... and then forget to ever look at them again until they fail.
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    jaggedben wrote: »
    The average person you sell your house to will smile, nod, say "let me take notes! I'm so excited about this!", leave their notes by the batteries .... and then forget to ever look at them again until they fail.

    That is true of anything that requires any maintenance. Some people do it. Others forget. Who knows how many cars were ruined because people forgot to change oil for years. But you wouldn't say cars need special understanding to be used, would you?
  • solarix
    solarix Solar Expert Posts: 713 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage

    In my years of solar, I have concluded that the average homeowner can't maintain batteries. Check the batteries every month - a'int gonna happen. People are so spoiled by the Utility taking care of their power needs that they can't get into a mindset of being responsible for themselves. Unless a person shows me that they are "into" solar enough to be hands-on and willing to do what it takes, I steer them away from off-grid. People want to be self-sufficient, they want to be green, but they don't want to pay more than the utility and they don't want to do maintenance. Well - there is no such technology. As much as we solar people and even the grid needs it, storage has a long way to go be viable. However, i think we may start to see grid-tied systems with small amounts of battery built in to provide stability, help ride through cloudiness, and even shift the generation peak later in the day.
  • jaggedben
    jaggedben Solar Expert Posts: 230 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    That is true of anything that requires any maintenance. Some people do it. Others forget. Who knows how many cars were ruined because people forgot to change oil for years. But you wouldn't say cars need special understanding to be used, would you?

    You missed the point. The point is that for people who are bad at these things (i.e. most people) it is better to have fewer things in their lives that require maintenance. People who ruin cars by not doing proper maintenance don't really have a maintenance free option to choose instead, but if they did that would be a good thing for them. Invent a maintenance free car and you'll make a fortune. (Actually, it's supposedly a selling point for EVs...)
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    jaggedben wrote: »
    You missed the point. The point is that for people who are bad at these things (i.e. most people) it is better to have fewer things in their lives that require maintenance. People who ruin cars by not doing proper maintenance don't really have a maintenance free option to choose instead, but if they did that would be a good thing for them. Invent a maintenance free car and you'll make a fortune. (Actually, it's supposedly a selling point for EVs...)

    Unlike cars, there's a maintenance-free version of batteries - AGMs.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage

    But the issue of cost remains. While PV costs keep coming down power watt, battery cost doesn't. My argument has always been, in a rational grid tie world, no one ought to use batteries, as all they do is increase the Wh cost of the power, and reduces the net efficincy by at least 20% so from a total energy consumptions/production issue, it makes no sense.

    That said, obviously the are local conditions that mess with the rational.

    Tony
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    solarix wrote: »
    In my years of solar, I have concluded that the average homeowner can't maintain batteries. Check the batteries every month - a'int gonna happen.

    This is so true. The area where my place is has about 5 or 6 other people with off-grid solar installed.
    Since it is such a small community and everyone gets along, I pretty much monthly go to everyone's place and do their battery maintenance for them. In return they generally provide a nice dinner, six-pack or barter with some services I need. Some offered to pay a monthly fee to me but that is not how things work out here :) All those people are "smart" people but like you said, just plain lazy sometimes. They are now so spoiled having power all the time the forget that THEY are creating it and need to maintain it.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    jcheil wrote: »
    solarix wrote: »
    In my years of solar, I have concluded that the average homeowner can't maintain batteries. Check the batteries every month - a'int gonna happen.

    This is so true. The area where my place is has about 5 or 6 other people with off-grid solar installed.
    Since it is such a small community and everyone gets along, I pretty much monthly go to everyone's place and do their battery maintenance for them. In return they generally provide a nice dinner, six-pack or barter with some services I need. Some offered to pay a monthly fee to me but that is now how things work out here :) All those people are "smart" people but like you said, just plain lazy sometimes. They are now so spoiled having power all the time the forget that THEY are creating it and need to maintain it.

    Your story actually disproves solarix's statement. There are 5 or 6 people in your area, and all of them found a perfectly good way to maintain their batteries by hiring a nice guy next door.
  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    Your story actually disproves solarix's statement. There are 5 or 6 people in your area, and all of them found a perfectly good way to maintain their batteries by hiring a nice guy next door.

    Well, not all of the world's people can operate in the socal structure the way our "community" does :)
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    ggunn wrote: »
    Battery maintenance is simple once you understand it, but the vast majority of people don't, and furthermore, they don't have any interest in understanding or dealing with it at all it.

    Agreed. Most people will simply not do it.

    I think the future will see more battery based installations because smart grid and TOU incentives will drive them - but they won't be the traditional lead acid 24/48V systems. First off there's the maintenance thing that is a dealbreaker for most people. Secondly in a modern system even 48 volts is a stupid voltage to choose. It's too low, and results in very large conductors/switchgear and higher losses overall, since it's hard to convert efficiently from 450 volt DC (array voltage) to 48 volt (battery voltage) back to 240 volts AC (final voltage.)

    In the future I think we will see more integrated LiFePO4 and Li-ion battery packs in the 200 volt to 400 volt range, primarily sourced from used EV packs. With tens of thousands of EV's being sold every year in the US - and with that number going up all the time - there will soon be a lot of timed-out batteries available that still have a lot of their life left. These are maintenance free, high voltage, well protected and modular (most are designed for easy change out) and provide a higher bus voltage for renewable energy systems. It's a lot more efficient to convert 450 volts to 400 volts and then to 240 volts.

    This will be accelerated by the growing demand for EV chargers; matching voltages makes it a lot easier to charge EV's. And once the higher voltages are common, then bidirectional use of EV's (and even hybrids) becomes easier. With a hybrid car and a HV DC power system in a house you easily have a week's worth of full power backup.

    The big missing piece now is the inverter/charger. Large UPS inverters often operate at higher voltages for reasons of efficiency, and people who use their hybrids for backup often use these inverters to provide power from the traction battery. (The Tripp-Lite SU5000RT4UHV for example; 5kW pure sine inverter that runs on 192 volts nominal, which means about 160 to 240 volts. This works well with a Prius traction battery.)

    However no major manufacturer that I know of has a high voltage DC inverter intended for RE applications - but I also expect that to change as batteries become more available and TOU/smart grid/renewable energy availability demands start increasing demand for local storage.
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    If I would sell my house to a person who do not know anything about batteries, I would tell - every three months, open caps on few cells and look how much water is there. If it is below certain level, pour this amount of water into every cell. After that, if you see some cells have less water than others, add a little bit to them. I don't think it requires any understanding, or desire to understand.

    If I had AGMs, even watering wouldn't be needed.
    But all that is tremendously more involved than having a GT system that you just turn on and walk away. And then there is the expense of batteries. Off grid systems are fantastic for making power where there is no grid, but where there is, battery systems are just not that attractive to most people.
  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage

    Or you can use EVs and PEVs to charge directly, instead of a stand alone battery bank. The best (IHMO) of all worlds.

    Tony
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    ggunn wrote: »
    But all that is tremendously more involved than having a GT system that you just turn on and walk away. And then there is the expense of batteries. Off grid systems are fantastic for making power where there is no grid, but where there is, battery systems are just not that attractive to most people.

    GT system has totally different purposes. I would guess people choose things based on their needs/wishes. If I need furnace, I won't buy a refrigerator even if it is easier to use.
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    GT system has totally different purposes. I would guess people choose things based on their needs/wishes. If I need furnace, I won't buy a refrigerator even if it is easier to use.
    That's what I'm saying.
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    ggunn wrote: »
    That's what I'm saying.

    Good.

    If people want to store energy they use batteries (usually called UPS). Nobody sees any problems with that.

    If people want to capture solar energy they buy solar panels.

    If they want both, they buy both panels and batteries. The fact they they have both, doesn't make it more cumbersome or difficult to maintain.
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    Good.

    If people want to store energy they use batteries (usually called UPS). Nobody sees any problems with that.

    If people want to capture solar energy they buy solar panels.

    If they want both, they buy both panels and batteries. The fact they they have both, doesn't make it more cumbersome or difficult to maintain.

    Well, I question the last statement. A PV system with batteries takes more effort to maintain than one without batteries. Some batteries require more maintenance than others, but batteries need TLC from time to time, as well as eventual replacement.
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    ggunn wrote: »
    Well, I question the last statement. A PV system with batteries takes more effort to maintain than one without batteries. Some batteries require more maintenance than others, but batteries need TLC from time to time, as well as eventual replacement.

    Say, someone has a battery based UPS.

    Then, he decides to instal an (unrelated!) GT solar array. How does this make battery care more complicated than it was?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,522 admin
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    Re: Time to Consider Solar Net Metering Alternatives: Storage

    Smaller battery based consumer UPS systems generally only have 30-60 minutes worth of energy storage to support the loads--And their batteries (or whole units) are usually replaced every 1-2 years (or after a major outage that took the battery dead).

    None of those options/behaviors are usually acceptable for an off grid power system.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    Say, someone has a battery based UPS.

    Then, he decides to instal an (unrelated!) GT solar array. How does this make battery care more complicated than it was?

    They now have to deal with regular battery replacement. Since it is unrelated to the GT solar array, if they forget, they lose their UPS but keep their grid tie system.

    If they install a hybrid system and do not maintain it, eventually they lose both their UPS and grid tie system.
  • ggunn
    ggunn Solar Expert Posts: 1,973 ✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    Say, someone has a battery based UPS.

    Then, he decides to instal an (unrelated!) GT solar array. How does this make battery care more complicated than it was?
    It doesn't, necessarily, and it doesn't relate to what I said. Having batteries demands more attention than not having batteries.
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    They now have to deal with regular battery replacement. Since it is unrelated to the GT solar array, if they forget, they lose their UPS but keep their grid tie system.

    If they install a hybrid system and do not maintain it, eventually they lose both their UPS and grid tie system.

    All that you say, guys, is very true. Batteries do need some basic maintenance (except AGMs). And you can ruin them if you skip it (as with everything that requires maintenance).

    I only cannot agree that a regular guy is not capable of doing the maintenance. Adding water is not a rocket science.

    For some reason anti-battery sentiment is very strong everywhere. I once came accross a different forum. Don't remember the exact name, something like Battery King. They were bashing batteries as terribly bad things and they banned out everyone who had a different opinion. But, in fact, there's no alternative for energy storage. If you want to store energy, that is the only practical choice. And it is indeed practical. People use it, and it works fine.
  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    Adding water is not a rocket science.

    It's also not as simple as adding a quart of oil to an engine. There's a lot to understanding when to add water, how to do it, how to protect yourself, how to not damage batteries etc.

    I was responsible for a largish battery bank made up of 24 T-105's for an off grid installation. I had goggles, gloves, a little funnel, bottles of distilled water, lists of instructions etc. for people who maintained the batteries. Nobody ever read the instructions. I would come in on a weekend and find a puddle of water on top of the battery where a cell had overflowed and green corrosion everywhere from the acid on top of the battery. The halfway competent people there gave up after a while because they'd get bits of acid on their pants somehow and end up with holes in their jeans. One day I saw a woman leaning over the battery bank to try to look into a cell, her necklace dangling across one of the terminals. (Fortunately it never contacted two at once.)

    When we finally decommissioned it the plywood beneath was black and almost completely dissolved from the spilled acid, and even the floor beneath was starting to rot out. The fans which vented to the outside had corroded and locked up, and about half the cabling was so bad it couldn't be reused.

    Most of those problems came from poor maintenance, but that was with me (someone who was willing to do it right) there about once a month along with several well-intentioned but busy people trying to maintain it.
    For some reason anti-battery sentiment is very strong everywhere. I once came accross a different forum. Don't remember the exact name, something like Battery King. They were bashing batteries as terribly bad things and they banned out everyone who had a different opinion.

    They're not bad, they just take a lot of care - and it's more care than most people want to give it.
    But, in fact, there's no alternative for energy storage. If you want to store energy, that is the only practical choice. And it is indeed practical. People use it, and it works fine.

    Keep in mind that lead-acid is not the only option any more. There's now more than one choice.
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    It's also not as simple as adding a quart of oil to an engine.

    Changing oil may be dangereous too. If you don't jack your vehicle properly, then got onder it and start unscrewing stubborn oil filter, and your car falls on you ...

    The point is, if they cannot do it, they need to hire someone to come and do maintenance for you.
    Keep in mind that lead-acid is not the only option any more. There's now more than one choice.

    Hopefully, by the time I need new batterieies, it will be something I can use. It would be really gread to get rid of these absorptions that take lots of time and ruin efficiency.
  • bill von novak
    bill von novak Solar Expert Posts: 891 ✭✭✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    NorthGuy wrote: »
    Changing oil may be dangereous too. If you don't jack your vehicle properly, then got onder it and start unscrewing stubborn oil filter, and your car falls on you ...

    The point is, if they cannot do it, they need to hire someone to come and do maintenance for you.

    Agreed in both cases. Cars now go to extremes (service-required lights, oil pressure warnings) to get people to change the oil and to warn them that there is about to be a problem. You'd need to do something similar with batteries if you were to have any hope of average homeowners maintaining them.
  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
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    Re: Time to Consider Solar Net Metering Alternatives: Storage
    You'd need to do something similar with batteries if you were to have any hope of average homeowners maintaining them.

    "If you don't water your batteries, the power is going to be switched off in 7, 6, 5 ... "

    This is not difficult to organize. My refrigerator does a similar thing and warns me when filter needs to be changed.

    There are also things as automatic waterers (which I wouldn't trust) that may help. Safety can be improved too with deeper non-spill wells, insulating terminal covers etc.