Powerwall 2: SGIP/Incentives

[SoundDaTrumpet]

Not surprised if the >2 Powerwall option was not offered because it is not mainstream. In my case, it is impossible for me discharge 3 Powerwalls at the equivalent rate of 6 Powerwalls (discharge requirements double). I would fail an SGIP audit in an instant. It would be safe to say that the SGIP residential rules are tailored for homeowners while SGIP large scale are tailored companies/utilities. Maybe I should not have mentioned it in the first place.

I would say to assume a >10kW system and expect to fall under "Large Scale," though permissible, may not be practical. One would have to be a very large consumer.

 

[zanary]

Not surprised if the >2 Powerwall option was not offered because it is not mainstream. In my case, it is impossible for me discharge 3 Powerwalls at the equivalent rate of 6 Powerwalls (discharge requirements double). I would fail an SGIP audit in an instant. It would be safe to say that the SGIP residential rules are tailored for homeowners while SGIP large scale are tailored companies/utilities. Maybe I should not have mentioned it in the first place.

I would say to assume a >10kW system and expect to fall under "Large Scale," though permissible, may not be practical. One would have to be a very large consumer.

IS the discharge requirement on a per daily basis, or just the case if it was possible to do a full discharge?

On an average day I consume around 14 to 18 of energy, so two Powerwall's are sufficient for my daily base (I normally discharge around 70% per day for the past 4 weeks), however during the summer months If I choose to run my 5 tons AC unit the entire day, my usage increases up to 48 to 53.

So, if I had four Powerwall's I would be discharging them all once or twice year when it's hot enough to use my AC for the entire day, but otherwise I only discharge around 70% of two of them on a daily average.

 

[Az_Rael]

According to the concierge I spoke with, the 2 PW limit for SGIP rebates was lifted the beginning of October.

Does anyone know where the 2 PW rebate limit was documented?

 

[zanary]

Does anyone know where the 2 PW rebate limit was documented?

If you go to the PG&E site, and expand the Energy Storage Incentive Rates, it tell you what qualifies for small residential scale vs. large scale.

Energy storage and generation incentives

 

[SoundDaTrumpet]

Per SGIP 5.3.3, discharge requirement is equivalent per year. 52/yr for residential, and 130/yr for commercial. So for 2 Powerwall residential (10kW), required to discharge 2PW x 13.2 kWh/PW x 2 x 52/yr = 1370 kWh total. For commercial, 3 Powerwall (15kW) x 13.2 x 130 = 5150 kWh. To qualify Powerwall for 100% federal ITC, the limitation is annual solar generation. Mix this in with the software/interconnect agreement limitation, one would have to produce the kWh with solar and consume all the kWH on the premises. Your energy habits match mine, I be hard pressed to discharge 5150 kWh because though my home generates 6000 kWh for solar, what happens if my batteries are routinely full then I can't discharge what I can't store. My consumption is 8000kWh/yr.

Just pointing out there's not point getting into larger than 10kW system if one can't execute to the requirements.

 

[Az_Rael]

If you go to the PG&E site, and expand the Energy Storage Incentive Rates, it tell you what qualifies for small residential scale vs. large scale.

Energy storage and generation incentives

So it's the definition of small residential being 10kW or less? The SCE website does not have that same info, so I searched the handbook. The only reference I found to 10kW was here:

So it sounds like they can allocate large scale funds to small residential if an individual power company wants to?

 

[bkp_duke]

I think I could reach those discharge requirements, possibly on 4 x PWs.

2 x Model S P85 driven each about 12k miles per year
2 x AC units, each dual zone, run an average of 50 days per year
2 x Electric Ovens (wife LOVES to bake)
Pool Pump running 8-14 hours per day

Just charging the cars at night from the batteries might come close to hitting that usage.

 

[commasign]

It would suggest that commasign is applying for the "Large Scale Storage" for >10kW systems. Large Scale Storage have a different set of discharging requirements.

Correct. Hence Phase 3.

With regard to the other questions about discharge, my house and EVs easily use 100+ kWh per day during the summer and 60+ kWh per day rest of year so it shouldn’t be too hard to meet the discharge requirements.

 

[Az_Rael]

I think I could reach those discharge requirements, possibly on 4 x PWs.

2 x Model S P85 driven each about 12k miles per year
2 x AC units, each dual zone, run an average of 50 days per year
2 x Electric Ovens (wife LOVES to bake)
Pool Pump running 8-14 hours per day

Just charging the cars at night from the batteries might come close to hitting that usage.

I could too. My system was initially sized as a 13kW solar plus 4 Powerwalls. We put 27k miles yearly on EACH of our Model S's, so I wasn't planning on using the 2 powerwalls I have slated for EV charging at all. Plus I live in the high desert so my AC runs for most of the year (it's still running now, actually).

Wish this whole process wasn't so complicated. We are sticking with just 2 PW, the risk of buying 4 then not getting any SGIP rebate too dicey for me.


But now I wonder if I added a 3rd PW, would I then get the SGIP under large scale, where I might not with only 2? Curses!

 

[commasign]

I think I could reach those discharge requirements, possibly on 4 x PWs.

2 x Model S P85 driven each about 12k miles per year
2 x AC units, each dual zone, run an average of 50 days per year
2 x Electric Ovens (wife LOVES to bake)
Pool Pump running 8-14 hours per day

Just charging the cars at night from the batteries might come close to hitting that usage.

That’s almost the same situation as me. 2 Tesla’s and lots of baking! The AC unit (we have two, but only 1 is on the powerwall) is killer. The days it’s 110 degrees with no nighttime delta breeze, I can deplete all 4 powerwalls by about 3am.

 

[bkp_duke]

I could too. My system was initially sized as a 13kW solar plus 4 Powerwalls. We put 27k miles yearly on EACH of our Model S's, so I wasn't planning on using the 2 powerwalls I have slated for EV charging at all. Plus I live in the high desert so my AC runs for most of the year (it's still running now, actually).

Wish this whole process wasn't so complicated. We are sticking with just 2 PW, the risk of buying 4 then not getting any SGIP rebate too dicey for me.


But now I wonder if I added a 3rd PW, would I then get the SGIP under large scale, where I might not with only 2? Curses!

Ideally I would not want to charge the cars at night either (due to the round trip efficiency loss), but if it meant being compliant with the rebate vs. not, then I would do it. Right now, I usually charge direct from solar during the day because I work from home.

Tesla/SolarCity is giving me grief about two circuits and not wanting to do a whole-house backup because of them. One of them is the Tesla Wall Charger, which I told them I would gladly swap down to a smaller breaker in order to be in the install compliance guidelines. If moving to a 3rd or possibly even 4th PW gets me around this, it might be worthwhile just to simplify the design and install.

 

[Kren]

Maybe some movement on Phase 3 (I have 4 Powerwalls, PG&E). Tesla sent me a docusign just now for the rebate application. For my $26,000 project the numbers work out to $18,500 rebate. Fingers crossed that it all works out.

What utility are you with? I am wondering how Tesla is moving in Phase 3 (step 3). Step 3 has not opened up yet...unless they are getting you in as a large scale project.

 

[commasign]

What utility are you with? I am wondering how Tesla is moving in Phase 3 (step 3). Step 3 has not opened up yet...unless they are getting you in as a large scale project.

PG&E. If Phase 3 isn’t actually opening up, maybe they’re just getting the paperwork ready.

 

[Princeb]

Just spoke to Swell who claimed that I can claim both SGIP and 30% Federal ITC (off total project costs). I have pre-existing PV solar. Swell sounded very confident that when speaking with their CPA's, the ITC will qualify.

Solarcity told me that ITC will not apply unless the PV is a new concurrent installation.

Who is correct?

 

[abasile]

Just spoke to Swell who claimed that I can claim both SGIP and 30% Federal ITC (off total project costs). I have pre-existing PV solar. Swell sounded very confident that when speaking with their CPA's, the ITC will qualify.

Solarcity told me that ITC will not apply unless the PV is a new concurrent installation.

Who is correct?

Someone previously shared this NREL document on TMC (can't remember who or on which thread):
https://www.nrel.gov/docs/fy17osti/67558.pdf

While larger-scale installations, not residential, seem to be the focus, I'm not aware that that matters. Here are two relevant quotes:

NREL assumes that energy storage added to an existing renewable energy system would be eligible for the same benefit as a new system (see graphic above), based on a precedent set by a 2012 private letter ruling that allowed a wind farm owner to add energy storage to an existing wind farm and claim the tax benefit.

[footnote] NREL does not provide tax, legal, or accounting advice. Readers are encouraged to seek professional assistance.

Also, my personal impression is that Tesla/SolarCity has been endeavoring to err on the side of caution when advising customers on government incentives. I think they'd prefer to sell Powerwall systems to customers who won't become overly disappointed or need to back out due to issues receiving an incentive. A few weeks ago, a Tesla rep advised me that SGIP uses a lottery system and not to count on it.

 

[dhu1]

Just spoke to Swell who claimed that I can claim both SGIP and 30% Federal ITC (off total project costs). I have pre-existing PV solar. Swell sounded very confident that when speaking with their CPA's, the ITC will qualify.

Solarcity told me that ITC will not apply unless the PV is a new concurrent installation.

Who is correct?

Technically, Solarcity is correct. The ITC only applies as a part of concurrent installation. Having said that and as with everything related to taxes, you can always give it a try and see if you get called out on it Just a function on how aggressive you are in claiming your deductions.

 

[SoundDaTrumpet]

Solarcity: The easy way to claim. Fits into the tax forms easily, and requires no tutoring of your CPA.
Swell: See https://www.nrel.gov/docs/fy17osti/67558.pdf. Requires more tutoring of your CPA.The tax forms aren't friendly for add-on energy storage system.

As I interpret the law, why should one be penalized for having pre-owning solar. It is obvious that batteries are not solar. It is just like how a new roof is not solar, so just because you need a new roof doesn't mean that the ITC applies to the roof even if it is used as a structure to hold up the solar panels. With the solar city claim, if true, technically, only the solar portion would be eligible, and not battery. What I said is just an illustration. Battery system for grid/energy management are allowable. US Code in 2016 also supports double dipping. It would be nice if the federal law makers pass a bill to clarify this. You practically have to read several government docs to come to a conclusion. It be good if something like this is written into law. Let me know when it happens.

 

[Princeb]

Solarcity: The easy way to claim. Fits into the tax forms easily, and requires no tutoring of your CPA.
Swell: See https://www.nrel.gov/docs/fy17osti/67558.pdf. Requires more tutoring of your CPA.The tax forms aren't friendly for add-on energy storage system.

As I interpret the law, why should one be penalized for having pre-owning solar. It is obvious that batteries are not solar. It is just like how a new roof is not solar, so just because you need a new roof doesn't mean that the ITC applies to the roof even if it is used as a structure to hold up the solar panels. With the solar city claim, if true, technically, only the solar portion would be eligible, and not battery. What I said is just an illustration. Battery system for grid/energy management are allowable. US Code in 2016 also supports double dipping. It would be nice if the federal law makers pass a bill to clarify this. You practically have to read several government docs to come to a conclusion. It be good if something like this is written into law. Let me know when it happens.

Very interesting, so according to this, existing PV is eligible for ITC. Wow. I don't have a CPA, just do Turbotax, so wonder which forms to use for taxes?

 

[Princeb]

So if battery is charged 100% by PV rather than grid, 100% ITC is eligible. How would they even determine that?

 

[miimura]

Just spoke to Swell who claimed that I can claim both SGIP and 30% Federal ITC (off total project costs). I have pre-existing PV solar. Swell sounded very confident that when speaking with their CPA's, the ITC will qualify.

Solarcity told me that ITC will not apply unless the PV is a new concurrent installation.

Who is correct?

You take the 30% ITC on your net cost after all other incentives, including the SGIP, not on the gross amount. The batteries must be charged from renewable energy to get the ITC. Percentages are specified in that NREL document. As with all things income tax related, it's all good until you get audited. You would have to prove that the system is following the rules.