[Darren Donovan]

Hi,
I just received a postcard promoting a $5500 rebate from the state for the purchase of a battery for energy storage. I have solar panels on the roof as well on the ground in the backyard. Apparently, this organization encourages people with solar panels get a battery to store excess energy, which I think is a great idea. I don't know much about battery storage, aside from the fact that the Tesla Powerwall is in very limited supply due to their gigafactory not running at max capacity. Their latest version of the Powerwall includes the inverter, priced at $5500, same as the rebate. Are there other options besides Tesla? FYI, the info on the rebate is here www.caenergy.org

 

[firehawk72]

Also take a look at Enphase Energy's system. It would be easy to install and great for any crazy tier rates you deal with; however, it doesn't work when the grid is down. It is a very interesting approach.

 

[!arry4pyro]

It funded from a California program called Self Generation Initiative Program (SGIP). Funding allocations were mad to PGE, SCE, and SDGE. I'm currently trying to use this program for a battery backed OF system for a rental property I own. Not sure what all the details are but the solar company I'm working with says the SGIP rebate on a Power Wall 2 is $5600, that, plus the 30% Federal Income Tax Credit essentially makes the battery free. SGIP funding is limited and will be allocated on a first come first served basis unless there are more applications than the funds can cover. In that case, the lucky winners are selected through a lottery. Applications will be accepted beginning May 1. I'm am pulling the trigger today or tomorrow in order to improve my chances of getting the SGIP rebate.

With the crazy costs of electricity in California and the constraints imposed by Net Metering 2.0 a battery backed system is worth the extra cost even if you don't get the SGIP rebate.

 

[!arry4pyro]

So I went ahead and contracted for a battery backed 4.1 KW system. 12 panels each with a SolarEdge Optimizer feeding a StorEdge inverter specially designed to work with a battery. The battery is a Power Wall 2 which I think is around 14 KWH. The StorEdge inverter accepts DC feeds from the panels of the battery. It has two AC outputs, one to the service panel the other to a subpanel for the battery backed circuits. If grid power goes down at night the StorEdge draws power from the battery to supply power (up to 15 amps at 240 VAC) to the battery backed circuits. If the grid goes down during the day when the sun is up the StorEdge operates in an off grid more providing power to charge the battery and the battery backed circuits.

In my area peak rates are a whopping $.50/KWH, and the peak period is late afternoon to early evening when solar system are not outputting a lot of power. So by charging the battery during the day with your solar power and drawing on it in the evening, you can save by my calculations, up to $7/day. Over the 10 years the battery is warrantied for a savings of over $25,000 could be realized.

Of course you can operate the same system without the battery and simply trade KWHs when the solar is operating for power from the grid in the evening. The problem with that is you will still have to pay what they call Non Bypassable Charges on each KWH drawn from the grid. I'm not sure but I think these NBCs are 1/2 to 2/3 the charge, so the savings would be only 1/2 to 1/3 of what you can get with a battery.

So how much was the battery? Despite internet accounts of $5500 my supplier charged $7500. The SGIP rebate if I'm lucky enough to get it is $5400 and the battery qualifies for the Federal Income tax credit of 30% which adds another $2250 for a total of $7750, which means the battery is essentially free.

Here's more on the SGIP

http://www.cpuc.ca.gov/sgip/

Note the funding is very limited for residential storage, only about $40 million in the San Diego area about enough for 740 applications. So it will go fast. Applications will be accepted from May 1. Rebates issued on a first come first served bases. If the number of requests received on the first day exceeds the amount available, the rebates will be issued from a lottery.

 

[bentbiker]

Larry, check for Private Message.