California solar calculator
Size a California home solar system from your electric bill — kW, panel count, roof area, true cost with no federal credit for 2026 installs, and payback.
Quick answer: At $0.336/kWh and 5.5 peak sun hours, a $200/month bill needs about 4.92 kW — 12 × 410 W panels covering ~24 m². Gross cost is ~$12,398 with no federal credit for systems installed after 2025, offsetting $2,400 a year for a ~5.2 year payback.
Your details
Ballpark, not gospel. Ballpark, not gospel. Sized at 78% real-world output with the California sun-hour average (north/south vary a lot) — confirm shading, roof angle and your utility's NEM 3.0 tariff with a local installer before buying. The savings math values all generation at your retail rate. Under NEM 3.0 net billing, exported power earns only ~5–8¢/kWh on average — real savings track how much you self-consume or store in a battery, not how much you export.
The 30% credit ended — what changed
The residential clean energy credit (26 U.S.C. § 25D) gave homeowners a 30% credit on solar installed from 2022 through 2025. The July 2025 tax law ended it: no credit is available for property placed in service after December 31, 2025. That is why every figure on this page is ~30% higher than pre-2026 guides show. If your system went live by the end of 2025, tick the box above to see the credit applied; leased systems may still benefit because the leasing company claims the commercial credit. Source: IRS — Residential Clean Energy Credit.
Typical California system sizes by monthly bill
| Monthly bill | System size | Panels (410 W) | Net cost (no 2026 federal credit) | Payback |
|---|---|---|---|---|
| $100 | 2.46 kW | 6 | $6,199 | 5.2 years |
| $200 | 4.92 kW | 12 | $12,398 | 5.2 years |
| $300 | 6.97 kW | 17 | $17,564 | 4.9 years |
Computed at $0.336/kWh, 5.5 peak sun hours and $2.52/W installed, with no federal credit for 2026 installs. Export savings assume self-consumption at the retail rate — under NEM 3.0, exported power earns far less (see below).
Solar in California: the details
Solar cost in California
California installs cost more than the national average but the country's highest electricity rates compress the payback anyway. The EnergySage marketplace averaged about $2.52 per watt installed in 2026, with market quotes typically $2.50–$3.50/W. High rates mean small systems do big work: a $200/month bill needs only ~4.9 kW, grossing around $12,400, with no federal credit for 2026 homeowner installs.
Batteries are now the norm, not the upgrade: most 2026 California quotes pair panels with storage, and a battery adds roughly $10,000+ to the ticket.
Export rules: getting paid for surplus power
California runs NEM 3.0 — a net billing tariff, not net metering. Since April 2023, new PG&E, SCE and SDG&E interconnections earn avoided-cost export credits that vary by hour and season: roughly 5–8¢/kWh on average (midday off-peak as low as 2–5¢), rising to 10–25¢/kWh in the summer 4–9 PM peak window. That is ~75–80% below the old NEM 2.0 retail credit.
Self-consumed solar still offsets the full retail rate (~34–35¢/kWh), which is why the winning design under NEM 3.0 is west-facing panels + a battery that discharges through the 4–9 PM peak. The tariff survived legal challenge — the state Supreme Court declined further review in June 2026, so it is settled law. Municipal utilities (LADWP, SMUD) run their own separate programs.
California solar incentives
State solar rebate: none left. The big general battery rebate (SGIP) closed to new applications at the end of 2025; only a small income-qualified program remains, and it is waitlisted. What still works:
Property tax exclusion (Rev. & Tax Code §73) — solar adds $0 to your assessed value, but only for systems with utility permission to operate before January 1, 2027, so this window is closing. Smaller utility battery offers exist (SMUD, PG&E outage-zone rebates, Clean Power Alliance). New-build homes are a special case: California's Title 24 code already requires rooftop solar on new single-family homes.
Is solar worth it in California?
Verdict: yes — but only with the right design. The calculator's ~5.2-year payback assumes you self-consume at California's punishing retail rates; exporting midday power at 5¢/kWh tells a much worse story. Under NEM 3.0, solar without storage is a half-measure — size the battery on the solar system calculator, face some panels west, and the math holds up strongly.
Questions people actually ask
Straight answers, no fluff. Then run your own numbers above.
How many solar panels do I need in California?
It follows your bill. At the California average of $0.336/kWh and 5.5 peak sun hours, a $200/month bill needs about a 4.92 kW system — roughly 12 × 410 W panels covering ~24 m² of roof. High rates mean small systems do big work.
What is the average cost of solar panels in California in 2026?
The EnergySage marketplace averaged about $2.52 per watt installed in 2026, with market quotes typically $2.50–$3.50/W. A $200/month bill needs only ~4.9 kW, grossing around $12,400, with no federal credit for 2026 homeowner installs. Batteries add roughly $10,000+.
What is NEM 3.0 and how does it affect my savings?
NEM 3.0 is California's net billing tariff (in effect since April 2023 for PG&E, SCE, SDG&E). Exports earn avoided-cost credits of roughly 5–8¢/kWh on average — about 75–80% below the old retail-rate net metering. Self-consumed solar still offsets the full ~34–35¢/kWh retail rate, which is why west-facing panels plus a battery win under NEM 3.0.
What solar incentives does California still offer?
No state rebate remains. The property tax exclusion (Rev. & Tax Code §73) still applies to systems with utility permission to operate before January 1, 2027. The general SGIP battery rebate closed at the end of 2025; only a waitlisted income-qualified program remains. Smaller utility battery offers exist.
Is the 30% federal solar tax credit still available?
Not for homeowner purchases anymore. The residential clean energy credit (26 U.S.C. § 25D) is not available for property placed in service after December 31, 2025, under the July 2025 tax law (Public Law 119-21). Systems installed by the end of 2025 can still claim 30%, and leased systems may still benefit because the leasing company claims the commercial credit instead. (Source: IRS — Residential Clean Energy Credit.)
Is solar still worth it in California under NEM 3.0?
Yes with the right design. The ~5.2-year payback assumes self-consumption at California's high retail rates; exporting midday power at ~5¢/kWh tells a much worse story. Under NEM 3.0, pair panels with a battery and face some panels west to capture the 4–9 PM peak.
Do new California homes have to have solar?
Yes, for new construction. California's Title 24 building code requires rooftop solar on new single-family homes (typically ~2.5–5+ kW depending on climate zone and floor area). It does not apply to existing homes.
Figures last checked October 2026. Sources: EIA Electric Power Monthly (July 2026: 33.61¢/kWh), NREL PVWatts/NSRDB (~5.0–6.5 peak sun hours), DSIRE, California Public Utilities Commission; IRS — Residential Clean Energy Credit.
More US solar calculators
Compare other states: Texas, Florida, Arizona, North Carolina. And the national US solar calculator for country averages.
Comparing quotes? The solar cost calculator breaks down cost per watt and the solar ROI calculator maps your payback year by year. Going deeper: installation cost guide, how net metering works, how much you can save with solar and the solar batteries guide.