California incentive, go battery now or wait?

[djrobsd]

With the California rebate program, assuming I got approved for it, does it make sense to go battery storage now, or to wait?

I am in SDGE territory, so I am grandfathered into the current TOU schedule for 5 years. However, after that, battery will be much more attractive to properly manage any changes the utility might make to the TOU schedule. Right now TOU clearly favors solar, but I heard in 5 years they will change that schedule for the peak 48 cent time to be 4-8pm when solar is not really producing.

So, the battery in essence is future proofing my system. With all federal and state incentives applied, my cost of the Tesla Powerwall 2 out of pocket is roughly $1500. It seems like a pretty good deal.. But maybe it might be better for me to wait 5 years for the new TOU schedule to kick in.. By then battery prices will come down.. although state and federal incentives might be gone.. So it's kind of a gamble.

[sensij]

If you buy the battery now, in 5 years time it might need to be replaced. To qualify for the SGIP, you need to discharge on average 14% of the battery's capacity each day, and with solar, at least 75% of the battery charge is supposed to come from the array (which is energy you *aren't* getting peak credit for under current favorable TOU hours). You also need it professionally installed and monitored... are you sure that is only $1500 out of pocket?

Powerwall 2 has 13.5 kWh... in its most favorable usage right now (probably not allowed by the SGIP rules, but just in case), let's say you discharge 10 kWh daily during peak at $0.506 / kWh, and you pay $0.227/kWh off-peak to charge. 90% round trip means 11.1 * .227 = $2.52 per day in charging costs, and $5.06 in credit. That is a net of $2.54 / day.

If you've done the analysis in more detail and would like to share, please do.

[SunEagle]

I am not sure the Powerwall 2 is readily available yet for most people. I have seen other battery companies that are actually selling their product. I believe Aurora Energy has something that is similar to the P2 and works with solar edge inverters. Although even with a rebate from the state I think the total installed cost will be high.

[outie]

I got a quote for one Powerwall2 from Tesla/SolarCity. The battery is $5,500 + $700 backup gateway + $900 installation + $150 permit + taxes. The tier 1 rebate was supposedly oversubscribed already on 5/1. The Tier 2 goes for 0.4/Watt so the rebate is still a significant amount of ~$5k.

[SunEagle]

I got a quote for one Powerwall2 from Tesla/SolarCity. The battery is $5,500 + $700 backup gateway + $900 installation + $150 permit + taxes. The tier 1 rebate was supposedly oversubscribed already on 5/1. The Tier 2 goes for 0.4/Watt so the rebate is still a significant amount of ~$5k.

Sounds like you may have an opportunity to financially justify that battery.

Where are you located that you can get a $0.40/watt rebate on energy storage systems and how does that relate to a battery that is rated in kWh?

[sensij]

Sounds like you may have an opportunity to financially justify that battery.

Where are you located that you can get a $0.40/watt rebate on energy storage systems and how does that relate to a battery that is rated in kWh?

Google "SGIP", California's self generation incentive program. I linked some information when DanKegel opened a thread on the topic a month or so ago. Lots of formulas in the handbook to explain how the incentive is calculated, and rules to follow to regularly cycle the battery (no incentive for systems intended only for emergency backup).

Even with the incentive, the numbers didn't pencil it for me, but I'd love to be wrong and see analysis that concludes differently.

[J.P.M.]

Google "SGIP", California's self generation incentive program. I linked some information when DanKegel opened a thread on the topic a month or so ago. Lots of formulas in the handbook to explain how the incentive is calculated, and rules to follow to regularly cycle the battery (no incentive for systems intended only for emergency backup).

Even with the incentive, the numbers didn't pencil it for me, but I'd love to be wrong and see analysis that concludes differently.

FWIW, I came to about the same conclusion. I did find the handbook useful.

More FWIW, at this time, and probably a bit off topic, being in the asset distribution phase of my life, and since (for now anyway) I've got more $$ than brains, while both of those assets hold out (?? !!), and once EV's and residential energy storage get a bit more developed, and if those things get a bit closer to cost effectiveness, I'll probably spring for adding an EV and storage to my life even though I'm pretty sure they're not going to be anywhere close to cost effective any time soon, and see for myself how they do on meeting the hype and cost effectiveness claims, using the same logic as I did when I acquired a Sunpower panel system - way overpriced, but lets see how it performs in terms of annual output (same annual output as other non S.P. quality systems), and cost effectiveness ( LCOE ~~ $0.185/kWh for Sunpower vs. LCOE of ~~$0.136/kWh using $3.30/Watt estimated for other equipment).

Take what you want of the above. Scrap the rest.