There are a few companies that sell Powerwalls other than Tesla directly. In general, they are more expensive than Tesla directly, but installation with a 3rd party may qualify for the SGIP incentive and offset the difference. As you are in northern California, you are likely in PG&E territory and may make it into Step 4 ($3,480.00 credit/Powerwall).
Below is a very short list of companies to consider:
(Why get a Powerwall?)
Do you guys think this is worth pursuing? Is the SGIP guaranteed or is there a possibility that I both overpay and get nothing? Will it make the installation timeframe (significantly) longer?
I am planning at 12kW system and was looking for 2-3 powerwalls but its very hard to justify the cost without SGIP. I will probably only get 1 (or none at all) unless I can secure it.
What would you guys advise?