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Battery storage and solar

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brianman

Burrito Founder
Nov 10, 2011
17,620
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For the experts out there, have there been any federal or state incentives aimed at building out storage capacity at the home-owner level?

What made me curious:
If Tesla requires a large sums of batteries, Tesla might be able to convince Panasonic to open up a factory in California. This battery packs are not light and it might make some sense to produce them locally. The question boils down to where the materials for the batteries are sourced.

Thanks.
 
I think it would be a real game-changer if energy storage and energy efficiency inside a home were good enough so that a home could be 100% independent from the grid... at least for places in the southwest where there is more sun.
 
There has been some talk in the past about using old Tesla battery packs (that would still probably have 85-90% of their original capacity) alongside typical grid-tied solar PV systems, so that you could be independent of the grid. With a standard grid-tied PV system that does not have batteries, when the public grid goes down, you also go down, since they don't want you to back-fill the grid. Putting in batteries as part of a PV solar system would still qualify for the 30% Federal income tax credit, and possibly some state credits.

Of course this won't be feasible until people start replacing their battery packs, (either because a next generation battery pack is available or their original pack is actually old enough to show measurable degradation), which won't be for quite a while.

There has also been talk of using BEVs as a public utility grid buffer, so that your utility could draw from your vehicle battery (and give you a net-metering credit) if you were plugged-in during the day at home. You could control the times and the SOC level that you would allow. This is part of some of the "smart-grid" plans that are floating around.
 
I also would like to install on my apartment in the South of Italy a solar panel system completely independent from the grid. I am thinking to how to do it. Maybe I could start with a solar panel system not independent from the grid and then as soon as some batteries are available to modify it and to become independent from the grid. Or maybe I could buy used Tesla batteries and to become independent from the grid immediately. I am studying this matter.
 
I think it would be a real game-changer if energy storage and energy efficiency inside a home were good enough so that a home could be 100% independent from the grid... at least for places in the southwest where there is more sun.

Why? Are you independent for your food production? Your clothing production? Even in the southwest, the sun doesn't shine at night. It's not obvious that being off-grid is the most cost-effective way of meeting your round-the-clock energy needs, or that storing your excess daytime power into batteries for your nighttime use is the most sensible use of your peak power production. There are tangible "network economies" to being part of a larger whole.
 
Why? Are you independent for your food production? Your clothing production? Even in the southwest, the sun doesn't shine at night. It's not obvious that being off-grid is the most cost-effective way of meeting your round-the-clock energy needs, or that storing your excess daytime power into batteries for your nighttime use is the most sensible use of your peak power production. There are tangible "network economies" to being part of a larger whole.

From NYT:

On Rooftops, a Rival for Utilities - NYTimes.com
In Arizona, for example, the country’s second-largest solar market, the state’s largest utility is pressuring the Arizona Corporation Commission, which sets utility rates, to reconsider a generous residential credit and impose new fees on customers, months after the agency eliminated a commercial solar incentive. In North Carolina, Duke Energy is pushing to institute a new set of charges for solar customers as well.

I am hearing this as a more frequent argument from solar antagonists. Their argument basically that with net metering, utilities are not making much money off of residential solar owners who only use the utility line for backup. So therefore, they argue that solar owners should pay a special fee to pay for the infrastructure they are benefiting from. Now, my rebuttal to that argument is that if you are going to charge a special fee for using the utility company's infrastructure, then you should make everyone else do it too, not just solar customers. But with a special monthly fee, I'm not sure if the economic benefits of solar would work out as great as they currently do. Being off-grid would eliminate this problem, but it's hard to say if the additional investment is worthwhile.
 
Two thoughts from having attended the session Robert.Boston moderated at TESLIVE. Thanks to mknox and rolosrevenge (and the other guy, formerly with Better Place), who made up the panel.

1. You wouldn't even have to provide battery power from your grid-tied Model S in order for there to be value to the grid operator. All that's needed is for the grid operator to be able to throttle your charge rate. You'd specify a maximum charge rate and a time by which charging had to be finished, and the operator would vary the rate of charge as it desired to perform grid balancing, for which you'd be paid. This would obviously require new charging software in the S that negotiates charging rates with the grid operator.

2. The current pricing model, where the relatively few residences that have solar PV systems are allowed to sell power to the grid while being charged nothing more than a nominal monthly metering fee, is unsustainable in the long run. Grid infrastructure must be paid for, somehow, even if every customer is a generator as well as a consumer of electricity.
 
I think it would be a real game-changer if energy storage and energy efficiency inside a home were good enough so that a home could be 100% independent from the grid... at least for places in the southwest where there is more sun.

With Time of Use (TOU) and Net Energy Metering (NEM) such as PG&E has in California, I can't see a financial incentive for most homeowners to install energy storage, let alone enough energy storage to go off the grid. With TOU, the homeowner sells solar energy to PG&E at more than twice the $/kWh rate as he pays during off peak hours, when an EV is charged at night. Storing solar energy that could have been sold to PG&E at a high $/kWh peak rate in order to use it during low $/kWh off peak hours doesn't pay out. Compared to TOU & NEM, energy storage is a money loser even if the storage was free. Beyond that, one would have to build an enormous amount of energy storage and/or a grossly oversized solar PV system to generate enough energy during the winter months to be self sufficient with solar and go off the grid.
 
I posted some pictures of the 6 Tesla 70kW bi-directional battery storage packs that are at the Barstow Supercharger site for those who are interested. The Tejon Ranch supercharger site has some too... but I don't have any pictures of those. See site thread.
 
Why? Are you independent for your food production? Your clothing production? Even in the southwest, the sun doesn't shine at night. It's not obvious that being off-grid is the most cost-effective way of meeting your round-the-clock energy needs, or that storing your excess daytime power into batteries for your nighttime use is the most sensible use of your peak power production. There are tangible "network economies" to being part of a larger whole.
There are, but if grid operators/generators insist on profit margins that are too "healthy", then off-grid may be the most cost effective solution in some situations. Ironically enough, owning a large EV probably isn't one of those situations (unless someone has a charging station to/from work they can hit up for a few hours every few days or so), but given how inexpensive solar is now I can think of situations where going off grid can be less expensive.

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I view that as valid pushback, since SCE can't tell where your power is coming from with a battery pack. Now, what they need to do to address this is come up with some way to monitor battery pack output to insure you aren't charging up at night and discharging in the day, rather than just deny a customer the ability to use their own energy storage system.
 
There are, but if grid operators/generators insist on profit margins that are too "healthy", then off-grid may be the most cost effective solution in some situations. Ironically enough, owning a large EV probably isn't one of those situations (unless someone has a charging station to/from work they can hit up for a few hours every few days or so), but given how inexpensive solar is now I can think of situations where going off grid can be less expensive.

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I view that as valid pushback, since SCE can't tell where your power is coming from with a battery pack. Now, what they need to do to address this is come up with some way to monitor battery pack output to insure you aren't charging up at night and discharging in the day, rather than just deny a customer the ability to use their own energy storage system.

All comes back to bad pricing models.

Anyway, hopefully solar and batteries will force the utilities hands because it would reduce usage costs and that would be great for PEV owners. Unfortunately, so far it's mostly a solar fee, instead of a real pricing correction.