An honest look at whether battery storage makes financial sense for your San Diego home.
Battery storage went from "nice to have" to "default recommendation" almost overnight when California switched to NEM 3.0. Whether a battery is actually worth it for your specific home, though, depends on your usage patterns, your utility plan, and how much you value backup power. This article walks through the real economics — not the sales pitch.
What a Battery Does for a Solar Home
Your solar panels produce the most power between roughly 10 AM and 3 PM. Your home uses the most power between 4 PM and 9 PM, when people get home, run AC, cook dinner, and charge cars. Without a battery, you export the midday surplus to SDG&E (at a low NEM 3.0 export rate) and then buy it back at retail prices in the evening. A battery flips that equation: it stores your cheap solar for use during the expensive hours.
The Backup Power Side of the Equation
If you've lived through a Public Safety Power Shutoff (PSPS) or a SDG&E grid outage, you know power reliability isn't a given anymore. A properly installed battery system can keep your refrigerator, lights, internet, and select circuits running for 8–24 hours during an outage — longer if the sun is up and your panels can recharge the battery during the day.
What It Costs
- Tesla Powerwall 3 (13.5 kWh): roughly $13,000–$16,000 installed
- Enphase IQ Battery 5P: roughly $9,000–$11,000 installed per 5 kWh unit
- Federal tax credit reduces effective cost by 26%
- SGIP rebate (California) can provide additional savings, especially for medical baseline or low-income households
When a Battery Definitely Pays Off
- You're on a time-of-use rate plan with high evening peak prices
- You consume most of your power in the evening (typical for working families)
- You're installing solar new under NEM 3.0
- You have a home medical device or other backup-critical load
- You live in a wildfire-risk area subject to PSPS events
When It Might Not
- You're grandfathered into NEM 2.0 and your current export credits are still high
- Your evening usage is genuinely low (small household, no AC, no EV)
- You don't care about backup power and your grid is reliable
The honest answer
Under NEM 3.0 in San Diego, for the majority of homeowners, a single battery improves both your financial return and your resilience. For a small minority — typically light evening users who don't care about backup — it doesn't move the math meaningfully.
How to Size It Correctly
Battery sizing should be based on your actual 12 months of SDG&E hourly usage data, not generic assumptions. A good installer will pull your green button data, model your typical evening loads, and recommend battery capacity that covers your evening usage with some headroom for outages. Oversizing is expensive and rarely necessary; undersizing leaves money on the table.
Bottom Line
For most San Diego homeowners installing solar in 2026, yes — a battery is worth it. The combination of NEM 3.0 export economics, high SDG&E evening rates, and increasingly frequent outages makes battery storage the new default. Get a quote that models both solar-only and solar + battery for your specific usage, and let the numbers decide.