What the tariff did to the case for storage
Since April 15, 2023, customers applying for interconnection have taken service on the net billing tariff pursuant to CPUC decision D.22-12-056. Net billing tariff customers are paid for exported electricity based on its value to the electric grid, determined by the Avoided Cost Calculator.
The Calculator quantifies the value of exported electricity at different times of day, based on the avoided cost to the utility of buying clean energy elsewhere. In practice that means a large gap between what a midday export is worth and what an evening kilowatt hour costs you.
A battery holds midday production until that evening window, converting a low-value export into an avoided purchase at a high-value hour. That is the whole financial mechanism, and it is why the advice changed so sharply after 2023.
Ask for it as arithmetic rather than as a recommendation: how many kilowatt hours per year would move through the battery, what is the value difference between exporting them and using them later, what does the storage cost, and over what period does the difference repay it.
The export values are published, so check them
The utilities are required to publish uniform machine-readable spreadsheets containing the retail export compensation rates on their respective websites. The values underneath any savings projection are public rather than proprietary.
Ask your installer which export values their projection uses and where they came from, then check them against the published spreadsheet. A discrepancy deserves an explanation, and simply asking the question changes the tenor of the conversation.
Look at the shape of the values across the day and the year, not only an average. The variation is the point of the tariff, and an averaged number conceals exactly the thing that determines whether storage pays.
Ask when the installer last updated their projection methodology. A model carried over from before April 2023, or copied from an older template, will overstate your return substantially.
Bill savings and backup are two different jobs
A battery can lower your bill and it can keep part of your house running during an outage. Those are separate capabilities that arrive in one piece of equipment, and buying for one while assuming the other is a common disappointment.
A grid-tied array without storage shuts down during an outage as a safety requirement, so that crews are not working on lines a rooftop system is energising. If outage cover matters at all, storage is not optional.
Ask which circuits stay live, for how long at a realistic load, and whether the battery recharges from the array while the grid is down. Then ask how a battery sized for bill savings differs from one sized for meaningful backup, because they are frequently not the same system.
Check whether you qualify for help. California's Self-Generation Incentive Program offers $850 per kilowatt hour under its Equity category and $1,000 per kilowatt-hour under Equity Resiliency for qualifying customers, with criteria set out in the SGIP Handbook.
What changed federally, and the battery incentive that remains
The 30 percent federal Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025. A cash or loan purchase made now receives no federal credit, and a quote that still applies it is overstating your return substantially. Check any projection line by line rather than trusting a summary figure.
Section 48E survives at 30 percent and is available to third-party owners of residential systems under leases and power purchase agreements. The credit still exists, it simply no longer flows to a homeowner who buys the system. Expect lease providers to lead with that, and ask what they claim and what of that value actually reaches you in the rate offered, then confirm with a tax advisor.
California's Self-Generation Incentive Program continues to provide incentives for battery storage installed on the customer's side of the meter, including systems that can function during a power outage. Its Equity and Equity Resiliency categories are aimed at lower-income, medically vulnerable and at-risk for fire communities.
Depending on the category a customer qualifies for, the incentive is $850 per kilowatt hour under Equity or $1,000 per kilowatt-hour under Equity Resiliency. Applicants have one year after reserving funds to meet programme requirements, which include enrollment in a qualified Demand Response program, and further criteria are in the SGIP Handbook. Ask whether you might qualify and confirm with the programme rather than treating a sales answer as final.