Powerwall 2: SGIP/Incentives

[wwhitney]

Isn't 'gross income' talking about your entire gross-income for that year? This just means we can't be taxed for the utility subsidy, because it's "not income".

This would be tangential to the net-cost calculation of the equipment for ITC.

The relationship is that if you were taxed on the rebate, then you wouldn't have to reduce the basis (net cost) of your equipment for the ITC calculation. But Title 26 Section 136 says both that you aren't taxed on a utility rebate [136(a)] and that as a result you have to reduce the basis for the ITC [136(b)].

Cheers, Wayne

 

[SoundDaTrumpet]

Thanks for validating my decision to take the ITC.

In our case, our electricity usage is high because of our two EVs, and it's going to get higher as we convert appliances from gas to electricity. At the same time, our PV generation, while very helpful, is limited by shade from beautiful, tall trees on surrounding properties. So we could certainly use more NEM energy credits.

I did think about doing some conversion to electric appliances. Having my longest power outage of 23 hours this past month really made me appreciate the availability of natural gas appliances; specifically the hot water and stove. It is unfortunate that higher-efficiency water heaters (>55 gallons) require electricity to operate.

Another thing - for those on NEM 2.0 with the California utilities, there are non-bypassable charges. For such customers, those charges create more of an incentive to consume one's own PV generation.

Good point!

 

[wwhitney]

A few comments on evaluating the economic effect of restricting a Powerwall to charge from solar only (to qualify for the ITC):

First, given the power company tariffs, the choice of Powerwall use methods is between time shifting consumption and time shifting solar production. The tariffs don't allow straight rate arbitrage, i.e. charging the Powerwall at off-Peak from the grid and discharging it during Peak, in addition to your existing solar.

I'll use my tariff, EV-A, for computations. It is untiered and has Peak M-F 2 to 9 p.m., S-S 3 to 7 p.m.; Part Peak M-F 7 a.m. to 2 p.m. and 9 p.m. to 11 p.m.; Off Peak all other times. During the Summer (May through October), rates are $0.45 / $0.25 / $0.12 per kWh; during the Winter it is $0.32 / $0.20 / $0.125 per kWh.

If you want to have backup capability, I think 10 kWh/day is too great a depth of discharge for one Powerwall, you might have a power failure when you have only 3.5 kWhs remaining in the battery. I suggest 7 kWh is a better choice.

For solar time-shifting, if your solar system is big enough to be producing enough non-Peak power, then you can use one Powerwall to timeshift 35 kWh/week of Part Peak production (weekdays) and 14 kWh/week of Off-Peak production (weekends) to Peak production. For consumption time-shifting, if you consume enough Peak energy, you can use the Powerwall to shift 49 kWh/week of Peak consumption to off-Peak consumption.

With the above assumptions in both uses cases the Powerwall is discharging 7 kWh/day during Peak periods. The only difference is the cost of electricity while the Powerwall is charging: in the solar production shifting use case, 39 kWhs of weekly charging (given the 90% roundtrip efficiency) is done during Part Peak times, while in the consumption shifting use case, all the charging is done during Off Peak times.

So the economic difference is 39 kWh/week times the rate spread between Part Peak and Off Peak. In the summer, the spread is $0.13/kWh, for a difference of $5.1/week * 26 weeks = $132. In the Winter the spread is $0.075/kWh, for a difference of $2.9/week * 26 weeks = $76. The total annual difference is $208.

If you are on NEM 2.0, then the analysis is more complicated. Also, in my case I don't consume 7 kWh/day during Peak periods, and in the winter my solar doesn't produce 7 kWh/day during non-Peak periods, so that's another inaccuracy.

Cheers, Wayne

 

[NuShrike]

A few comments on evaluating the economic effect of restricting a Powerwall to charge from solar only (to qualify for the ITC):

One should be able to completely model all of the complications and TOU with NREL's System Advisor Model. It allows configuring how much discharge you want your battery to perform before going back to grid.

There's some hand-hacking to be done for the electrical rates json to tune the TOU rates because the app doesn't allow in-app editing.

I've modeled enough to find that two PW would actually cost me more in NEM 2.0 credits and general losses (with SCE) vs one PW. This is also against TOU-A, TOU-B, TOU-T (somewhat), and TOU-EV1.

 

[abasile]

Having my longest power outage of 23 hours this past month really made me appreciate the availability of natural gas appliances; specifically the hot water and stove.

It is precisely because we'll be installing Powerwalls that we're able to feel comfortable switching major appliances from gas to electric.

If you want to have backup capability, I think 10 kWh/day is too great a depth of discharge for one Powerwall, you might have a power failure when you have only 3.5 kWhs remaining in the battery. I suggest 7 kWh is a better choice.

Yes, agreed. Cycling even 7 kWh might be a little high for a single Powerwall if you want to maintain a good backup reserve, particularly this time of year (close to the winter solstice). I based my thinking on having two Powerwalls.

For solar time-shifting, if your solar system is big enough to be producing enough non-Peak power, then you can use one Powerwall to timeshift 35 kWh/week of Part Peak production (weekdays) and 14 kWh/week of Off-Peak production (weekends) to Peak production. For consumption time-shifting, if you consume enough Peak energy, you can use the Powerwall to shift 49 kWh/week of Peak consumption to off-Peak consumption.

With solar time-shifting, I believe you're limited to weekdays only. You won't get significant solar production during the very lowest rate periods ("off peak" for PG&E, "super off peak" for SCE), and Saturday/Sunday rates stay the same (mid-tier) from morning til evening.

With PG&E, it also appears that you've got a smaller spread, relative to SCE, between your lowest rates and your mid-tier rates. Even with a significantly longer "payback" for not claiming the ITC, however, I would still place value on having the flexibility to charge the Powerwall(s) at any time.

 

[CMXI]

I'm pretty excited to see these developments happen for consumers.

 

[wwhitney]

I based my thinking on having two Powerwalls.

Ah, I missed that, thanks.

With solar time-shifting, I believe you're limited to weekdays only. You won't get significant solar production during the very lowest rate periods ("off peak" for PG&E, "super off peak" for SCE), and Saturday/Sunday rates stay the same (mid-tier) from morning til evening.

That's not true of the PG&E EV-A rates, in fact you get more economic benefit from solar time-shifting on the weekend than you do on weekdays. Per the schedule I listed, the weekend daytime is split between off-peak and peak (3-7 p.m.) while the weekday daytime is split between part-peak and peak (2-9 p.m). So on the weekend you can time shift solar production from off-peak to peak, while on the weekday you are just time-shifting solar production from part-peak to peak.

Cheers, Wayne

 

[shinne]

I was going to get a powerwall to go with the solar system I was looking into. I was able to get Tesla to bring down their price via their price matching. I asked about the SGIP from the Tesla salesman who i'm working with. He that he put my name down but chances are we're going to little to nothing because he doesn't want to guarantee something that he doesn't know will happen.

The other solar company I talked to was LA Solar Group. The salesrep said he can get us in step 2 for sure. I like their price but I'm sure Tesla will match it. I was thinking about getting the batteries through them but I was quoted 12000 for the installation where Tesla is 7000.

I want to go with Tesla but I think LA Solar Group will give the better price. Difficult decision ahead. Has anybody else gotten news about their SGIP application?

 

[bkp_duke]

Received word, and verified with the online SGIP sheet, that our application for 3 PW's under "Large Storage" is now pending.

Step 2 rebate group, Tesla as the installer.

 

[abasile]

LA Solar Group, based on my experience with them, is a good company. We were happy with our solar installation with them.

For a single Powerwall, though, an additional $5000 above Tesla's quote seems like a steep price to pay just to be guaranteed an SGIP rebate that's probably not worth any more than about $5000! I don't know what your chances of getting the rebate would be if Tesla applies on your behalf, however. Some posters here are using Tesla as their installer and applying for SGIP on their own, but Tesla discourages this.

Tesla's Powerwall installation quotes are already more than reasonable and I would not expect them to come down in price. However, in my experience, Tesla/SolarCity has negotiated on solar installation prices. They may be able to match LA Solar Group if comparing apples to apples.

If you want/need the best possible solar panels with the highest possible efficiency, though, then having LA Solar Group install premium SunPower panels may be the way to go. Perhaps they might be willing to give you a better price (maybe close to $10K?) on a single Powerwall as part of the same install, which wouldn't be too bad if they can guarantee that you'll get an SGIP Step 2 rebate. My primary motivation for putting SunPower panels on our roof was that our roof space is quite limited and we wanted as much solar generation as possible. Otherwise, with much more available roof area, I probably would have been okay with cheaper "commodity" panels.

Something else to consider is whether a single Powerwall will be enough for you. Circuits with breakers larger than 30 amps cannot be backed up unless you install two or more Powerwalls. You might also find that you appreciate having more battery capacity to work with. If you want two or more Powerwalls, then I don't think it makes sense, price-wise, to go with any installer other than Tesla.

I was going to get a powerwall to go with the solar system I was looking into. I was able to get Tesla to bring down their price via their price matching. I asked about the SGIP from the Tesla salesman who i'm working with. He that he put my name down but chances are we're going to little to nothing because he doesn't want to guarantee something that he doesn't know will happen.

The other solar company I talked to was LA Solar Group. The salesrep said he can get us in step 2 for sure. I like their price but I'm sure Tesla will match it. I was thinking about getting the batteries through them but I was quoted 12000 for the installation where Tesla is 7000.

I want to go with Tesla but I think LA Solar Group will give the better price. Difficult decision ahead. Has anybody else gotten news about their SGIP application?

 

[wwhitney]

For a residential customer placing a new order with Tesla for Powerwalls today, I thought it would be interesting to comparing pricing on 1, 2, or 3 Powerwalls, based on the assumption that Tesla's capacity for the SGIP Small Residential Storage is full booked in all steps, but that there is availability for SGIP Large Storage Step 2. [For SCE customers, Step 2 is already sold out, so it would be Step 3.]

My quote for 1 Powerwall was $7,700 and change, which includes the hardware ($5,500 for the Powerwall, $700 for the Gateway), $800 for installation, $150 for permitting, and sales tax (9.25%) on the hardware. So I'll assume 2 Powerwalls would be $13,700 and 3 Powerwalls would be $19,700. This is pretty much the best case scenario, no other upgrades required.

For 1 or 2 Powerwalls with no SGIP rebate, the only incentive is the ITC. [Edit: I'm assuming an adequately large solar system and charging the Powerwalls only from solar.] After that 30% incentive the net cost without SGIP is $5,400 for 1 Powerwall or $9,600 for 2 Powerwalls.

For 3 Powerwalls, the SGIP Large Storage category requires that the system size (in kW) be no greater than the customer peak demand over the last 12 months. Residential rate plans don't include any demand charges, so residential meters just record energy used over an interval of time (either 15 minutes or 60 minutes). The imputed demand for the interval is the just the average power used over an interval. So to qualify for 3 Powerwalls under SGIP Large Storage, you need to have had an interval during the last 12 months in which you used 15 kW average over that interval. 15 kW = 62.5A @ 240 V.

Assuming you make it over that hurdle, the Step 2 incentive rate is $0.40/Wh without the ITC, or $0.29/Wh with the ITC. Using a discharge duration of 2.7 hours (some use 2.64 hours), the incentive per Powerwall is $4,700 without the ITC, or $3,400 plus change with the ITC.

So for 3 Powerwalls under the Step 2 SGIP Large Storage, the out of pocket cost if not taking the ITC would be $5,600. If taking the ITC, the cost after SGIP before ITC would be $9,500, and after the ITC it would be $6,650. Odd.

The upshot is that for a new Tesla Powerwall residential customer who could qualify for SGIP Large Storage for 3 Powerwalls (12 month peak demand is at least 15 kW), with the above minimum installation costs, it's bascially a buy 1 get 2 free situation: $5,400 net for 1 Powerwall, or $5,600 net for 3 Powerwalls. Of course, if you can find a non-Tesla developer who won't gouge you on the installation costs, then under SGIP Small Residential Storage Step 2, the cost of 1 Powerwall would be less then $5,400. [If my attempt to self-develop pans out, then it would be $3,000 for me with SGIP only, or $2,100 if I also took the ITC.]

Cheers, Wayne

 

[Kren]

Just a reminder...
The SGIP is hosting a Quarterly Workshop at the Pacific Energy Center on Friday December 15th, 2017. Registration and call-in details will be shared to the service list and to current program participants at a later date.[check website for call-in and online participation details]

To ensure a robust agenda with relevant topics, the SGIP Administrators would like to hear from stakeholders on potential discussion topics in addition to the items listed below. Please contact one of the Program Administrators listed below with your requests. We look forward to seeing you at the workshop!
"While we can’t speak on behalf of Tesla, we are happy to clarify any aspects of the program that may be unclear."


Agenda Topics:

-New Developer Application

-New Equity Budget

-New Inspection Sampling Protocol

-Publicizing Equipment Vetted by the SGIP Technical Working Group


Pacific Gas and Electric (PG&E)
[email protected]
(877) 743-4112

Center for Sustainable Energy (CSE)
[email protected]
(858) 244-1177


SoCalGas
[email protected]


Southern California Edison
[email protected]
(626) 302-0610

 

[abasile]

Tesla just told me that, with them handling our SGIP application, we'd likely be too far back in the queue for Tier 3, and we'll likely end up in Tier 4 or Tier 5. For reference, we paid an initial Powerwall deposit to Tesla in late August 2017, we signed a contract with Tesla in mid October, and we now have a March 2018 installation date.

The Tesla rep indicated that, to get around the 20% developer cap that applies to Tesla installations, one would need to use a third party installer. He recommended that if a Tesla customer hasn't already started their own SGIP process as a homeowner, that they not begin this process. Tesla is concerned that independent homeowner/developer SGIP applications, when submitted by Tesla customers, will count against Tesla's 20% developer cap or not be accepted at all. This is a conservative position that's not without justification, given the ambiguity we've seen with SGIP.

From the standpoint of the SGIP administrators, I truly believe the best solution would be to eliminate the developer cap after a certain number of days have elapsed in each step and category. For example, if after 30 days there remain unclaimed Step 2 Small Residential funds for SCE customers (which is already the case), then the developer cap should be removed. Then, when Step 3 begins, the 20% developer cap should apply for the first 30 days. This would still give third party installers a chance without locking out Tesla customers. The alternative would be to encourage a bunch of homeowner/developer applications, but that would create more administrative overhead and hassle for everyone.

I intend to call the SCE SGIP administrator to make this recommendation, and I'll try to participate in this Friday's SGIP workshop.

 

[Kren]

Tesla just told me that, with them handling our SGIP application, we'd likely be too far back in the queue for Tier 3, and we'll likely end up in Tier 4 or Tier 5. For reference, we paid an initial Powerwall deposit to Tesla in late August 2017, we signed a contract with Tesla in mid October, and we now have a March 2018 installation date.

The Tesla rep indicated that, to get around the 20% developer cap that applies to Tesla installations, one would need to use a third party installer. He recommended that if a Tesla customer hasn't already started their own SGIP process as a homeowner, that they not begin this process. Tesla is concerned that independent homeowner/developer SGIP applications, when submitted by Tesla customers, will count against Tesla's 20% developer cap or not be accepted at all. This is a conservative position that's not without justification, given the ambiguity we've seen with SGIP.

From the standpoint of the SGIP administrators, I truly believe the best solution would be to eliminate the developer cap after a certain number of days have elapsed in each step and category. For example, if after 30 days there remain unclaimed Step 2 Small Residential funds for SCE customers (which is already the case), then the developer cap should be removed. Then, when Step 3 begins, the 20% developer cap should apply for the first 30 days. This would still give third party installers a chance without locking out Tesla customers. The alternative would be to encourage a bunch of homeowner/developer applications, but that would create more administrative overhead and hassle for everyone.
I intend to call the SCE SGIP administrator to make this recommendation, and I'll try to participate in this Friday's SGIP workshop.

That is a great idea, lifting developers cap after 30 days. Definitely there is a concern with self-submitters counting against Tesla's developers cap. I understand Tesla's position on that. In order not to do this you have to stretch the truth, just a little, when listing your development activities.

 

[wwhitney]

Hmm, 7 weeks since I applied for a Developer key and still waiting. Only one response from [email protected], 4 weeks ago. Very frustrating!

I found that I had the Approved Developers List from October 13, 2017. That list has about 70 homeowners approved, and my count for the current list from December 8, 2017 is about the same (I could easily have miscounted by one or two). So there have been basically zero homeowners approved as developers in the last two months.

Cheers, Wayne

 

[shinne]

Just realized that I think LA Solar Group is going to charge me $6000 after the SGIP rebate. Which is around what Tesla is charging me. I'll have to confirm with them but if that's the case, it's not worth going with LA Solar Group if i'm getting the same price for everything. That's kind of disappointing if that's the case.

 

[shinne]

Just got a quote from Swell Energy. This price seems amazing but something feels off about their ITC rebate. They're doing 30% off total amount. Was this assumed to be correct?

 

[wwhitney]

Nope, the ITC is to be calculated from your net cost after SGIP rebates. Please review the last 20% or so of this thread for details.

Cheers, Wayne

 

[NuShrike]

Hmm, 7 weeks since I applied for a Developer key and still waiting. Only one response from [email protected], 4 weeks ago. Very frustrating!

It's only been 2 weeks+ for me since I applied for the dev key, under the new application form, but seems I'm in the same boat as you.

I'd emailed them yesterday (SCE) for an update. They said forwarded to the group handling it, and then so far nothing .... They sure don't look like they're approving any keys at this point.

@shinne I got similar quote from Swell late Oct 2017, but closer to $21K for two. They seem to be gouging as it shouldn't be an extra ~$4K installation for the 2nd PW2 (single PW2 quote is $12334). Here's another similar thread for calculating SGIP v ITC: SGIP rebate for Powerwall 2 install in SCE territory?

 

[shinne]

Thanks @NuShrike. From calculating everything it seems like there's no difference in pricing if I were to go with Swell.

I got quoted from Tesla for a Powerwall and install is ~$7500 so after ITC it's around $5250. Someone said that their two powerwalls cost $13000, so after ITC it's 9100.

If I do the calculations with Swell the correct way, it's going to be around 9100 also but the down side is that i'm stuck having to discharge. Basically all the rebate money went to Swell.

Really wish I could get on Tesla SPIG but doesn't look like there's any chance.