Home batteries
Home batteries in California: size, cost and SGIP
What a battery is, how big yours should be, what one costs installed in California right now, and whether the state rebate can help.
Checked . Sources linked in the text.
By the Golden Hour Energy editorial team. How we research and check our guides
A typical home battery in California holds about 13 kWh and costs about $13,500 installed before incentives. That's the average EnergySage reports for California, from data updated October 18, 2026 (EnergySage). Whether that money comes back depends on how much power you use in the evening, what your utility charges then, and whether you can get any of the state's SGIP rebate, which is mostly closed right now (selfgenca.com).
What the hardware does
A battery doesn't make power. It moves power from when your panels make it to when you need it. It charges from the midday surplus and runs the house after the sun drops. Set up for backup, it also keeps chosen circuits running in an outage. Why that shift pays on SCE and SDG&E bills is a billing question, covered in our NEM 3.0 guide.
What it costs, and how long it takes to pay back
EnergySage's California marketplace data puts the average at $1,037 per kWh of storage. For a 13 kWh system that's about $13,482 before incentives, with most systems between $11,460 and $15,504 (EnergySage, updated October 18, 2026). Those are averages from quotes on one marketplace, not prices for your home. Panel upgrades, wiring distance and the number of batteries all move the number, and only a licensed installer can give you a real one after a site review.
On payback, one 2026 analysis estimates about 6 to 9 years for solar with a battery under NEM 3.0, compared with 9 to 12 or more for solar alone (Jouleio). The spread is wide because homes are different. Big evening users on SDG&E tend to see the fastest returns. Light, daytime users see the slowest.
Sizing basics, without the jargon
Battery size is measured in kilowatt-hours (kWh), the same unit on your bill. The common mistake is sizing to your whole day. You don't need to. The sun covers the daytime. The battery only has to cover what's left. Four questions get you most of the way:
- How much do you use after the sun drops?
- This is the load a battery replaces. Your utility's hourly data shows it. Look at late afternoon to bedtime on a typical summer day.
- What should stay on in an outage?
- Fridge, lights, Wi-Fi and a few outlets need far less than central AC or a pool pump. Whole-home backup takes more capacity.
- Can your panels refill it?
- A battery only helps if there's enough midday surplus to charge it. Panel size and battery size have to be designed together.
- What's changing at home?
- An EV, a heat pump or a new baby can move your evening use a lot. Plan for the next few years, not last year.
A simple example, using made-up round numbers: say your home uses about 12 kWh between late afternoon and bedtime on a summer day. A battery that can deliver roughly that much, charged by panels that make enough extra at midday, could cover most of your evening. If you also want the whole house running through a long outage, you'd need more. An installer should do this math from your hourly usage. The CPUC's disclosure rules expect them to use your one-hour interval data or explain why they couldn't (CPUC).
Ask about the settings
The same battery can be set to save the most money, to hold a reserve for outages, or a mix. The CPUC's “Before you sign” checklist tells buyers to have the installer walk through those settings. Ask which one your savings estimate assumes.
SGIP in 2026: where the battery rebate stands
The Self-Generation Incentive Program (SGIP) is California's battery rebate. Its funding moves in steps, and each utility area has its own budget. On October 26, 2026, the program's metrics page showed general market small residential storage closed at SCE, PG&E, SoCalGas and the Center for Sustainable Energy, which runs SGIP in SDG&E territory. Equity resiliency was closed at all four, and most of the remaining state-funded equity money was waitlisted (selfgenca.com). The ratepayer-funded budgets aren't coming back: they took their last applications at the end of 2025. Our SGIP rebate guide covers the one budget still running and who qualifies.
| Topic | Who it's for | Status |
|---|---|---|
| General market | Most homeowners, $150 per kWh | Closed in SCE and SDG&E areas |
| Equity resiliency | Eligible households, $1,000 per kWh | Closed in SCE and SDG&E areas |
| Other equity funds | Income-qualified households | Mostly waitlisted |
If an installer builds a big SGIP rebate into your numbers, ask which category they're counting on and whether you've been confirmed for it. Don't sign based on a rebate that might not come through. The CPUC also lists programs for income-qualified homeowners at cpuc.ca.gov/solarguide/lowincomesolar.
The federal homeowner credit no longer covers batteries either. What's left of federal credits is in our 2026 tax credit guide, and whether to buy or lease one is in the lease vs buy guide.
When a battery isn't worth it
- You're on LADWP's standard plan. LADWP isn't on NEM 3.0 and nets exports against use, so a battery there is mostly for backup. See LADWP solar.
- Your evening use is tiny. If the house is quiet after sunset, there's little for a battery to replace.
- You're on older NEM 2.0 solar. Adding a battery to an existing system may affect your plan. Ask your utility first.