Powerwall 2: SGIP/Incentives

[Az_Rael]

I don't think you will be able to identify your application

Well, there are only 7 Palmdale residential installs in the real time database, and none of them list Tesla as the developer, so I am guessing I will be able to identify it when it shows up.

But getting the application number is a great idea, since I am not entirely convinced that what my sales rep is telling me is correct. (He hasn't been the most consistent source of information so far).

 

[Kren]

Well, there are only 7 Palmdale residential installs in the real time database, and none of them list Tesla as the developer, so I am guessing I will be able to identify it when it shows up.

But getting the application number is a great idea, since I am not entirely convinced that what my sales rep is telling me is correct. (He hasn't been the most consistent source of information so far).

Oh Oh yeah, if you don't see a matching record I would be suspicious also that your application was not submitted. It was suppose to be for Step 2 right? If step 3 it wouldn't be there.

 

[Az_Rael]

Oh Oh yeah, if you don't see a matching record I would be suspicious also that your application was not submitted. It was suppose to be for Step 2 right? If step 3 it wouldn't be there.

No, I believe it’s for step 3, which is why I am confused/suspicious. He said my application had already been submitted to SCE and the state, but earlier told me Step 3, and there is no way both of those things can be true. SGIP won’t accept Step 3 stuff until it opens.

Tesla is not taking any SGIP applications anymore, so if it turns out he is wrong about my application, odds are I will have to self submit.

 

[Kren]

No, I believe it’s for step 3, which is why I am confused/suspicious. He said my application had already been submitted to SCE and the state, but earlier told me Step 3, and there is no way both of those things can be true. SGIP won’t accept Step 3 stuff until it opens.

Tesla is not taking any SGIP applications anymore, so if it turns out he is wrong about my application, odds are I will have to self submit.

Well, hopefully he is just misinformed. If he told you step 3, I am sure you are in their queue but do not have an application with SGIP. I received this reply when I asked Tesla how the priority for their SGIP application process works. "We are working to get SGIP approvals for customers on a first come, first serve basis, based on the signing of the Initial Contract". Unfortunately, no one has any information when Step 3 will open. Also unfortunate is it seems like they are changing the requirements for self-submitters. If they don't open step 3 for another 3-6 months, who knows what the requirements will be for a homeowner submitting their own application.

 

[Kren]

Self-Generation Incentive Program (SGIP) Quarterly Workshop Notice
SGIP put on their website information on how to join the personal conference through audio or online. SGIP |

 

[Az_Rael]

If they don't open step 3 for another 3-6 months,

Considering you have to apply within 12 months of an install, I wonder how many Tesla Step 3 folks will become ineligible prior to the Step opening up. Unless no one is actually doing installs yet, and the wait list is only contracts.

I expect to install in the next month, which will start my 12 month clock. Will be interesting to see how Tesla handles that.

 

[jeep1979]

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?

While investigating the ITC I came across the following:

Summary: S.1868 — 115th Congress (2017-2018)All Information (Except Text)
Listen to this page
There is one summary for S.1868. Bill summaries are authored by CRS.

Shown Here:
Introduced in Senate (09/26/2017)
Energy Storage Tax Incentive and Deployment Act of 2017

This bill amends the Internal Revenue Code to allow tax credits for: (1) energy storage technologies, and (2) battery storage technology.

The bill expands the tax credit for investments in energy property to include equipment that: (1) receives, stores, and delivers energy using batteries, compressed air, pumped hydropower, hydrogen storage (including hydrolysis), thermal energy storage, regenerative fuel cells, flywheels, capacitors, superconducting magnets, or other technologies identified by the Internal Revenue Service; and (2) has a capacity of at least five kilowatt hours.

The bill also expands the tax credit for residential energy efficient property to include expenditures for battery storage technology that: (1) is installed on or in connection with a dwelling unit located in the United States and used as a residence by the taxpayer, and (2) has a capacity of at least three kilowatt hours.

---------

This would seem to indicate that if you try and take the ITC in its current form it may be rejected for adding batteries to an existing installation. I was thinking about trying to take it, but after seeing this proposed senate bill, I'll think I'll wait and see what happens with it.

 

[Kren]

Considering you have to apply within 12 months of an install, I wonder how many Tesla Step 3 folks will become ineligible prior to the Step opening up. Unless no one is actually doing installs yet, and the wait list is only contracts.

I expect to install in the next month, which will start my 12 month clock. Will be interesting to see how Tesla handles that.

Most people (I believe) are not installing unless they have confirmation from SGIP that they have rebate funds reserved from them. Tesla will/would send a contingency letter if someone asked for it stating that if you don't get SGIP confirmation you can back out. At least that is what they did before they reached their developers cap in all steps. Tesla has a huge queue of people signed up but not installing.

 

[wwhitney]

2. Alternatively, I do wonder if they could still wire it where it's Meter- > Gateway -> Main Panel -> new Sub Panel AND original sub panel for the entire house. Is it a legit practice to pass the wire from the meter thru the main (without landing) direct to gateway and return back to main power to power the whole house (say if you wanted to backup your Tesla Wall Connector)?

Electrical wiring from the power company up until the first breaker is service wiring. The NEC does not allow service wiring to cohabit conduits or enclosures with other premises wiring. So the part about having service conductors travel from the meter to the Backup Gateway (with Main Breaker, so it is the Service Entrance) through the Main Panel is not allowed.

Cheers, Wayne

 

[wwhitney]

I want to file for the SGIP rebate my self. Does anyone have the the technical specs needed such as: Amp-Hour Capacity of Each Battery,Nominal Battery Voltage, and Continuous Power Output of Inverter? I can't get through to my Tesla rep. He insists that customers can't apply for the rebate on their own. SGIP says I can. I just need the technical info. Thanks in advance. -K

OK, I'm trying to apply as a homeowner/developer for the SGIP, and I just reviewed this entire thread.

The Amp-Hour question is answered by the equation:

Rated Capacity (Watt-Hours) = Rated Amp-Hours * Rated Voltage

The current spec sheet says the internal DC voltage is 50V, and gives a capacity of 14 kWh, 13.5 kWh usable. So the answer for Amp-Hours is 280 or 270, depending on which figured is used.

There's also the question of the "Inverter Output Efficiency", but I'll leave that alone for now.

Cheers, Wayne

 

[wwhitney]

Another SGIP application question:

The SGIP applicaiton process makes a distinction between "energy storage" and "energy storage paired with and charging from an onsite renewable generator." The threshold for the paired category is that 75% of the energy used to charge the energy storage should come from the onsite renewable. I understand that if claiming the ITC, the paired category is required. And the paired category qualifies for priority in the event of an SGIP lottery, but that advantage is no longer useful. The paired category also seems to have greater reporting requirements. So if not applying for the ITC, is there any advantage to the applying for the SGIP as paired storage? It seems easier and more flexible in the future to not apply as paired storage.

Thanks,
Wayne

 

[Kren]

Another SGIP application question:

The SGIP applicaiton process makes a distinction between "energy storage" and "energy storage paired with and charging from an onsite renewable generator." The threshold for the paired category is that 75% of the energy used to charge the energy storage should come from the onsite renewable. I understand that if claiming the ITC, the paired category is required. And the paired category qualifies for priority in the event of an SGIP lottery, but that advantage is no longer useful. The paired category also seems to have greater reporting requirements. So if not applying for the ITC, is there any advantage to the applying for the SGIP as paired storage? It seems easier and more flexible in the future to not apply as paired storage.

Thanks,
Wayne

I noticed that also. I did initially fill out my application without the paired storage specification. They kicked it back to me, put my status as RFF Suspended and had me redo the section of the application that deals with on-site generation. Now, I don't know for sure what triggered this, possibly there was some contradiction on the application they spotted, numbers not adding up, etc. I have no idea. But I just decided to not cut any corners and fill it out the right way. Perhaps if I was more savvy with electrical systems and data I could have filled out the applicaton without specifying pairing.

 

[wwhitney]

I did initially fill out my application without the paired storage specification. They kicked it back to me, put my status as RFF Suspended and had me redo the section of the application that deals with on-site generation.

Did your initial application indicate you were planning to take the ITC? If so, that then would a contradiction, as the ITC requires the storage to be paired with a renewable generator.

If not, then I don't see why they should kick it back, I don't see anything in the Handbook that says storage has to be paired with a renewable generator. Or even a requirement that if you have a renewable generator on site, then you have to configure the storage as paired storage and charge it 75% with renewables. That would be like a penalty to having solar, if the SGIP program put more requirements and restrictions on battery storage with solar than it does on battery storage without solar.

Seems to me that if you have solar but don't plan to claim the ITC, then applying for the SGIP without paired storage is a win administratively, as then there is no requirement for a monitoring plan.

Cheers, Wayne

 

[Kren]

Did your initial application indicate you were planning to take the ITC? If so, that then would a contradiction, as the ITC requires the storage to be paired with a renewable generator.

If not, then I don't see why they should kick it back, I don't see anything in the Handbook that says storage has to be paired with a renewable generator. Or even a requirement that if you have a renewable generator on site, then you have to configure the storage as paired storage and charge it 75% with renewables. That would be like a penalty to having solar, if the SGIP program put more requirements and restrictions on battery storage with solar than it does on battery storage without solar.

Seems to me that if you have solar but don't plan to claim the ITC, then applying for the SGIP without paired storage is a win administratively, as then there is no requirement for a monitoring plan.

Cheers, Wayne

I just checked my first application. I remember now, I did mark of that I was pairing with a renewable. I marked it off at the very last minute before submitting. I was concerned that I was falsifying information that would be discovered at some later point in the application process. It sounds like you are saying that specifying that you are pairing is only necessary when you are claiming the ITC and the SGIP doesn't care otherwise. I did not realize that. I am glad that I did it now and CAN claim the ITC. But filling out that paperwork was a real headache and I may still have additional paperwork difficulties after install.

 

[wwhitney]

OK, I'm at the point of applying to be a homeowner/developer where my RRF application is ready to be submitted but I am still waiting for a developer key. I thought I'd give an overview of the process for anyone else interested in doing this:

1) Get a developer key. SGIP | Developer Registration For me this has been the slowest part, apparently the process has changed from the early posts in this thread. I submitted the older form on October 27, which is around the time the newer form came out. I got a response 3 weeks later asking for more information. I submitted further information referencing the developer activities listed in CPUC Resolution 4887, http://docs.cpuc.ca.gov/PublishedDocs/Published/G000/M197/K216/197216880.PDF (well, actually I referenced a draft version I found) I see that the new developer application form has these 13 developer activities listed already.

Note also that the definition of developer for steps 3 and later has changed from the original definition, which is apparently still in force for step 2. The new definition explicitly recognizes homeowner developers; in the older definition it was somewhat of a gray area. So it is possible that homeowners will face difficulty in getting developer keys until step 3 opens.

2) Apply for an account on selfgenca.com, SGIP | I got an email back saying, in effect "are you really going to apply yourself as the homeowner?" A fairly simple response along the lines of "yes, and I'm applying for a developer key as well" was sufficient to have an account generated.

3) Sign into your selfgenca.com account, go to the dashboard and create a new draft application. This consists of two parts, filling out the Reservation Request Form (RRF) on line, and then uploading supporting documents. For these materials, the handbook (https://www.selfgenca.com/documents/handbook/2017) is the authoritative reference, I will summarize my understanding of the relevant portions below.

4) For the RRF, there are multiple panels to fill out. On application type, if your power company is PG&E or SCE, that is your Program Administrator. Otherwise see the handbook. The Application Type is Energy Storage, and if you are applying for 1 or 2 Powerwalls, the Budget Category is Small Residential Storage. If you are applying for 3 or more Powerwalls, the Budget Category would be Large Scale Storage, but (a) I haven't read the Handbook details on that, a bunch of different provisions apply, and (b) at present, Tesla has not hit its Step 2 Developer Cap for Large Scale Storage ($18M out of $20.7M), so hopefully you could just get Tesla to be the developer and handle the application.

Under Developer Contact you will need to enter your developer key, once you get one.

Under Contractor/Installer Contact, that would be Tesla. You can't self-install unless you have a California license type A, B, or C-10, and even then you'd need to convince Tesla to sell you the Powerwalls directly. Tesla's CSLB license number is 888104. For the contact info, in my case Tesla has already applied for a permit with my city, so I simply looked up the permit application and used the information entered on it.

Under Proposed System Information--Energy Storage, a battery is Electrochemical Storage, the equipment is Tesla Powerwall 2 AC. For a single Powerwall I am using Total Rated Capacity 5 kW, Total Energy Storage Capacity 13.5 kWh, and Discharge Hours Duration 2.7 hours. The first two figures are per the latest spec sheet, the last figure is just the ratio. Now most of the applications that have been submitted so far (https://selfgenca.com/report/public) for the Powerwall 2 AC show a Total Energy Storage Capacity of 13.2 kWh, which means the Discharge Hours Duration would be 2.64 hours. I don't know where that figure came from, and some of the applications do show 13.5 kWh, so I'm going with the current spec sheet. You will need to fill out the Energy Storage Sizing worksheet, see below.

Now if you don't have solar (or other self generation) then you can answer no to the 75% renewables question and the other self generation equipment question. If you do have solar, then you need to specify that and fill out the panel Other Onsite System Information. You also need to make a decision on whether to choose to charge the Powerwalls a minimum of 75% from your solar. Doing so would allow you to also (partially) claim the ITC, although since that reduces your SGIP incentive, I'm not convinced that is much of a financial win. Doing so also increases your reporting requirements, see below. I have solar but am applying without pledging to charge the Powerwall 75% from solar.

Under Utility Information, you will need to provide your electric service account ID and meter number. For PG&E and SoCalGas I think the gas account info is also required (for some reason these two power companies require you to submit a gas bill in addition to an electric bill, see below.)

Under Project Finance you indicate the total cost of the installation, whether you are applying for the ITC (which will reduce your SGIP rebate), and whether you are getting other incentives.

I think the rest of the RRF panels are self-explanatory. I'll continue with a discussion of the required documentation to submit in a subsequent post.

Cheers, Wayne

 

[wwhitney]

OK, a bunch of supporting documents are required for the Reservation Request Form (RRF) submittal:

1) The RRF itself, signed. Once all the panels are complete, you need generate the form, print it out, sign it, scan the signed copy, and upload.

2) Copy of Executed Contract or Agreement for Installation. I used the 8 page "Powerwall Purchase & Home Improvement Agreement" that Tesla sent. That document was undated, so I also included my email "Your order has been confirmed" from Tesla. Perhaps it would have been better to print out the 8 page agreement, sign and date the last page, scan it back in, and upload it.

3) Energy Efficiency Audit. This is basically a hurdle to jump through, although if you haven't done any energy efficiency upgrades on your house, you might learn something in the process. See section 5.4.2.4 of the Handbook. In my case I submitted two online generated PDFs: PG&E's Home Energy Checkup Save energy with a home-energy audit and LBL's Home Energy Saver Home Energy Saver

4) Equipment Specifications. I used the spec sheet available at https://www.tesla.com/sites/default/files/pdfs/powerwall/Powerwall 2_AC_Datasheet_en_northamerica.pdf

5) Proof of Electric Service. I logged into my pge.com account, downloaded my latest bill, and uploaded it

6) Proof of Gas Service. For some reason this is required for PG&E and for SoCalGas. I just uploaded the same bill, as it shows both electric and gas service.

7) Copy of Application Fee Check. A fee of 5% of the incentive amount (which is computed on the RRF) is due. I wrote out a check to the Program Administrator (not 100% sure that's the correct payee), which for me is PG&E Self Generation Incentive Program, and I took a photo of it and uploaded it. The handbook says "After a project is assigned to an incentive step, the application fee check must be mailed within 7 calendar days" to the Program Administrator.

8) Electric Load Documentation. My understanding is that this is not required for the Budget Category Small Residential Storage.

9) Storage Sizing Worksheet. This is a spreadsheet available at SGIP | Resources that is to be filled out with Amp-Hours (?), Battery Voltage (50V), Discharge Duration (?), Continuous Power Output of Inverter (5 kW), and CEC Inverter Efficiency (?). It outputs Total Energy Storage Capacity and Total Rated Capacity, which are entered into the RRF along with the Discharge Duration.

It is not clear to me how to fill this out, the Tesla spec sheet doesn't have all the necessary information. The answers you want to get are 5 kW Total Rated Capacity and either 13.5 or 13.2 kWh Total Energy Storage Capacity (and 2.7 or 2.64 hours Discharge Duration, respectively). Based on a battery voltage of 50V (per the spec sheet), the amp-hours should be either 270 or 280 depending on whether you used the 13.5 kWh available capacity or the 14.0 kWh nominal capacity. The spec sheet doesn't give an Inverter Efficiency, it only gives a round trip efficiency of 90%, but that round-trip efficiency is the product of inverter efficiency with charging efficiency and electrochemical efficiency. The instructions also refer to entering the inverter efficiency "if appropriate".

So one option is to enter 100% for the efficiency, on the argument that it is not appropriate for this product, and then 270 Ah and 2.7 Discharge Duration. This will give 13.5 kWh Total Energy Storage Capacity. I elected to guess that the inverter efficiency is 97% (approximately the cube root of 90%) and then used 280 amp-hours so that the answer was still 13.5 kWh, on the theory that the 13.5 kWh Usable spec is measured after the inverter. Another option would be to use 270 Ah, 2.64 Hours Discharge Duration, and 98% efficiency, on the theory that those numbers give you the 13.2 kWh Total Energy Storage Capacity seen on many other applications.

10) Other Supporting Documentation You need to download the Residential Energy Storage Affidavit from SGIP | Resources then print it, fill it out and sign it, scan it in, and upload it. I chose option A as I am on a TOU plan.

11) Preliminary Monitoring Plan This document slot will appear only if you select "yes" to the "charged at least 75% from renewables" question on the Proposed System Information -- Energy Storage panel of the RRF. You should select yes if you have solar and want to take the ITC. In which case SGIP | Resources has a PMP template and checklist to aid you in generating your PMP, which seems like a relatively big endeavor. I'm not going to claim the ITC, so I didn't check yes to the "75% from renewables" question, and therefore am not prompted to submit a PMP. If you are not going to claim the ITC, I'm not aware of any current advantage to checking yes to "75% from renewables", although I might have missed something in the Handbook.

And that's it, 9 or 10 documents to upload. Of course, I haven't submitted yet or had my reservation approved, so it could be I missed something.

Cheers, Wayne

 

[wwhitney]

Oh, and just as a preview, if you succeed in getting your reservation approved, have your Powerwall(s) installed, and want to claim your incentive, there are 4 (or 5) documents to be uploaded:

1) Incentive Claim Form: I'm guessing this will be populated by filling out panels, the same way the RRF was.

2) Final Building Inspection Report: Upload a copy of your finaled job inspection card or whatever documentation your building department gives you.

3) Project Cost Affidavit and Breakdown Worksheet: These forms are available at SGIP | Resources

4) Proof of Authorization to Interconnect: A document from your power company. Part of the paperwork to be done before installation is to request interconnection permission from your power company. Tesla typically handles the interconnection request; when it is granted your power company should send you a letter to that effect, which you need to upload.

5) Final Monitoring Schematic: If you had to submit a Preliminary Monitoring Plan, then this document will also be required.

Cheers, Wayne

 

[Kren]

OK, a bunch of supporting documents are required for the Reservation Request Form (RRF) submittal:

1) The RRF itself, signed. Once all the panels are complete, you need generate the form, print it out, sign it, scan the signed copy, and upload.

2) Copy of Executed Contract or Agreement for Installation. I used the 8 page "Powerwall Purchase & Home Improvement Agreement" that Tesla sent. That document was undated, so I also included my email "Your order has been confirmed" from Tesla. Perhaps it would have been better to print out the 8 page agreement, sign and date the last page, scan it back in, and upload it.

3) Energy Efficiency Audit. This is basically a hurdle to jump through, although if you haven't done any energy efficiency upgrades on your house, you might learn something in the process. See section 5.4.2.4 of the Handbook. In my case I submitted two online generated PDFs: PG&E's Home Energy Checkup Save energy with a home-energy audit and LBL's Home Energy Saver Home Energy Saver

4) Equipment Specifications. I used the spec sheet available at https://www.tesla.com/sites/default/files/pdfs/powerwall/Powerwall 2_AC_Datasheet_en_northamerica.pdf

5) Proof of Electric Service. I logged into my pge.com account, downloaded my latest bill, and uploaded it

6) Proof of Gas Service. For some reason this is required for PG&E and for SoCalGas. I just uploaded the same bill, as it shows both electric and gas service.

7) Copy of Application Fee Check. A fee of 5% of the incentive amount (which is computed on the RRF) is due. I wrote out a check to the Program Administrator (not 100% sure that's the correct payee), which for me is PG&E Self Generation Incentive Program, and I took a photo of it and uploaded it. The handbook says "After a project is assigned to an incentive step, the application fee check must be mailed within 7 calendar days" to the Program Administrator.

8) Electric Load Documentation. My understanding is that this is not required for the Budget Category Small Residential Storage.

9) Storage Sizing Worksheet. This is a spreadsheet available at SGIP | Resources that is to be filled out with Amp-Hours (?), Battery Voltage (50V), Discharge Duration (?), Continuous Power Output of Inverter (5 kW), and CEC Inverter Efficiency (?). It outputs Total Energy Storage Capacity and Total Rated Capacity, which are entered into the RRF along with the Discharge Duration.

It is not clear to me how to fill this out, the Tesla spec sheet doesn't have all the necessary information. The answers you want to get are 5 kW Total Rated Capacity and either 13.5 or 13.2 kWh Total Energy Storage Capacity (and 2.7 or 2.64 hours Discharge Duration, respectively). Based on a battery voltage of 50V (per the spec sheet), the amp-hours should be either 270 or 280 depending on whether you used the 13.5 kWh available capacity or the 14.0 kWh nominal capacity. The spec sheet doesn't give an Inverter Efficiency, it only gives a round trip efficiency of 90%, but that round-trip efficiency is the product of inverter efficiency with charging efficiency and electrochemical efficiency. The instructions also refer to entering the inverter efficiency "if appropriate".

So one option is to enter 100% for the efficiency, on the argument that it is not appropriate for this product, and then 270 Ah and 2.7 Discharge Duration. This will give 13.5 kWh Total Energy Storage Capacity. I elected to guess that the inverter efficiency is 97% (approximately the cube root of 90%) and then used 280 amp-hours so that the answer was still 13.5 kWh, on the theory that the 13.5 kWh Usable spec is measured after the inverter. Another option would be to use 270 Ah, 2.64 Hours Discharge Duration, and 98% efficiency, on the theory that those numbers give you the 13.2 kWh Total Energy Storage Capacity seen on many other applications.

10) Other Supporting Documentation You need to download the Residential Energy Storage Affidavit from SGIP | Resources then print it, fill it out and sign it, scan it in, and upload it. I chose option A as I am on a TOU plan.

11) Preliminary Monitoring Plan This document slot will appear only if you select "yes" to the "charged at least 75% from renewables" question on the Proposed System Information -- Energy Storage panel of the RRF. You should select yes if you have solar and want to take the ITC. In which case SGIP | Resources has a PMP template and checklist to aid you in generating your PMP, which seems like a relatively big endeavor. I'm not going to claim the ITC, so I didn't check yes to the "75% from renewables" question, and therefore am not prompted to submit a PMP. If you are not going to claim the ITC, I'm not aware of any current advantage to checking yes to "75% from renewables", although I might have missed something in the Handbook.

And that's it, 9 or 10 documents to upload. Of course, I haven't submitted yet or had my reservation approved, so it could be I missed something.

Cheers, Wayne

This is great. Thanks for being so detailed and writing it all out. Very helpful. Just two things: 1) For SCE, the sizing worksheet wasn't needed. They accepted the Tesla powerwall 2 spec sheet in lieu of. So I was able to get my application through without Amp hours, inverter efficiency and etc. just using the publicized Tesla specs. But the information is helpful and valuable as you never know when they decided to get more strict about this. 2) When I get time, I want to look this up for definite confirmation, but I believe they made an amendment removing the calculation of the ITC from the Small Residential rebate total.

 

[wwhitney]

2) When I get time, I want to look this up for definite confirmation, but I believe they made an amendment removing the calculation of the ITC from the Small Residential rebate total.

Thanks for taking the time to read through it all and compare it with your experience.

Your point on the ITC seems to be correct. Scanning the SGIP Handbook, it appears the SGIP incentives are only reduced for (1) Large Scale Storage claiming the ITC and (2) other utility rate payer funded incentives. And with the online RRF, indicating that you are taking the ITC doesn't reduce the SGIP incentive amount calculated unless the ITC + SGIP incentive amount would exceed the total project cost.

However, my understanding is that the equipment cost (basis) upon which the 22.5% to 30% ITC (30% prorated by the fraction of the charging of the Powerwall that comes from solar, with a minimum of 75%) needs to be reduced by any non-taxable incentives received for the equipment. Here is an excerpt from a 2010 IRS letter (https://www.irs.gov/pub/irs-wd/1035003.pdf):

Section 136 provides an exception to this general rule, stating that gross income
does not include the value of any subsidy provided (directly or indirectly) by a public
utility to a customer for the purchase or installation of any energy conservation
measure. Section 136(b) provides, in relevant part, that a taxpayer may not take a tax
credit (such as the credit under § 25D) for an expenditure to the extent of the amount
excluded as a subsidy under § 136(a) with respect to the expenditure.

Section 25D is the section for the residential solar ITC. I haven't looked up the relevant sections themselves or looked for later controlling IRS rulings or letters; I'm just going on the above for a preliminary analysis. The SGIP certainly sounds like it meets the criterion listed to be both excluded from gross income and to require a basis reduction for the solar ITC.

So my 1 Powerwall quote comes to $7,723.50, and if I get a Tier 2 rebate with a 13.5 kWh Storage Capacity and 2.7 hour Discharge Duration it will be $4,700. Thus my basis would be $3,000 plus change, and so the ITC would be worth $675 to $900. Plus I would need to figure out if the restriction of charging the Powerwall 75% to 100% from solar would reduce the economic value of the Powerwall for time shifting solar production and peak consumption.

My first impression is that dealing with the PMP and the monitoring and the extra tax forms isn't worth $675 to $900 to me, but I'll mull that over. If the ITC were calculated on the full equipment cost, it would probably be a different story, I would probably be tempted to get 2 Powerwalls in that case.

Cheers, Wayne

 

[abasile]

So my 1 Powerwall quote comes to $7,723.50, and if I get a Tier 2 rebate with a 13.5 kWh Storage Capacity and 2.7 hour Discharge Duration it will be $4,700. Thus my basis would be $3,000 plus change, and so the ITC would be worth $675 to $900. Plus I would need to figure out if the restriction of charging the Powerwall 75% to 100% from solar would reduce the economic value of the Powerwall for time shifting solar production and peak consumption.

While I'm not an accountant, your logic as to the ITC seems sound. I'm of the same opinion. That said, if I rightly recall, there are posts upthread which assert that it's possible to claim the ITC based on the full cost while simultaneously receiving the full SGIP rebate.

I agree that if the ITC isn't worth a great deal, then it's probably not worth claiming. With no ITC requirements to worry about, we could charge the Powerwalls from the grid during "super off peak" hours, if supported by Tesla, and get the maximum possible economic benefit from TOU load shifting and solar PV NEM credits. Skipping the ITC could also give us the freedom to "top off" the Powerwalls from the grid whenever there's a big snowstorm up here in the mountains that threatens to simultaneously knock out our grid power and bury our solar panels. (That said, "snow" seems like a foreign concept right now, as it's already December and we haven't seen a single flake yet.)

With continued growth in solar PV deployments, I expect that the late morning hours will eventually have to be designated as "super off peak", at least during Spring. That would push homeowners like us to charge our batteries during those hours instead of exporting our solar production.