Normally, Powerwalls in the US are programmed by Tesla to only charge from solar, for customer who have solar. In the event of an audit, it doesn't seem that it should be difficult to provide the IRS with documentation to corroborate this.
The only concern is that Storm Watch mode entails charging from the grid. Oral statements from Tesla Energy employees, by themselves, probably shouldn't be taken as tax advice. If it's in writing from Tesla, then that would be a bit more solid. Best would be to have guidance in writing from the IRS. While the likelihood of being audited is low, you never know.
Perhaps one option in claiming the ITC could be to declare the Powerwalls as being 99% charged by solar, just to leave room for occasional use of Storm Watch mode. This would be a question for a tax accountant, of course. On the other hand, if those high-level NWS alerts are very infrequent, then perhaps this is truly not worth worrying about.
So this is where I get confused.
Your statement of "Powerwalls in the US are programmed by Tesla to only charge from solar, for customer who have solar." is only partially true. They are programmed to charge from only solar until the feds (NWS) issues a severe weather alert, which then tells the Powerwall that it is permitted to be charged from the grid.
I agree about the written statements from the IRS, however since both IRS and NWS are federal agencies, I would have to go with the notion that allowing Tesla to force Powerwalls to charge from the grid (when approved by NWS) is an agreement between all three (IRS, NWS and Tesla), along with the different power grid operator or maybe their association group.
In terms of calming the ITC, isn't this as simple as completing the 5695 (
https://www.irs.gov/pub/irs-pdf/f5695.pdf) form? Maybe I'm missing something, but are you suggesting that we as homeowners need to attest to some sort of statement for ITC?
Note: In my case, I installed Powerwalls back in Sept 2017 and by themselves they do not quality for any sort of federal tax credit (including ITC). I did enroll in California's GSIP program which sent me a rebate check of $9200 back for my original $13,800 I spent on them (out the door with Tesla, including installation). I installed Tesla Solar in 2018, so the cost of my Panels + inverter was around the same, for which I plan to claim ITC. I just need to complete 5695 to get my 30% tax credit for my 2018 Solar install.
For those wondering, the reason why I split up my system is this.
My Powerwall installation (after all rebates) was $4600
My 3.2kw Tesla system (after all tax credits) was $9100 - I'm limited by roof space so 3.2kw is all I could install.
Total cost of my 3.2kw + 2 Powerwalls was $13700
Now I'm curious about this.
(a) How do people get audited for ITC? The ITC program has been running for over 5 years now, so I assume someone must have been audited or ask for evidence.
I leave my entire system, on Advance - Time Savings, and since I'm on the PG&E EV-A rate tariff, I set my peak, partial-peak and non-peak hours in the app, and let it do all the magic of when to consume from the Powerwall, grid, and solar, and when to sell back to PG&E.
as the famous infomercial used to say "set it and forgot it".
