Solar panels in San Francisco, CA
Roofs in San Francisco get about 1,819 hours of usable sunlight a year — more than 85% of the cities we've measured. Here's what that means in cost, savings and payback, using real rooftop data rather than a national average.
Check your specific roof in San Francisco → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical San Francisco solar system costs
A 18-panel system (7.2 kW) is about right for an average San Francisco home using 10,800 kWh a year. It would produce roughly 11,132 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 4,948 | $6,384 | $1,252 | 5.1 yrs |
| 12 panels | 4.8 kW | 7,422 | $9,576 | $1,407 | 6.8 yrs |
| 16 panels | 6.4 kW | 9,895 | $12,768 | $1,561 | 8.2 yrs |
| 20 panels | 8 kW | 12,369 | $15,960 | $1,715 | 9.3 yrs |
| 26 panels | 10.4 kW | 16,080 | $20,748 | $1,947 | 10.7 yrs |
Notice that payback barely improves as systems get bigger, and eventually gets worse. That's because you can only save money on electricity you were going to buy anyway. Once a system covers your usage, extra panels mostly generate exports at a much lower rate.
Why San Francisco gets 1,819 sun hours
That figure comes from Google's analysis of real rooftops across San Francisco — it already accounts for shading from trees, chimneys and neighbouring buildings, which is why it's lower than the raw "hours of daylight" figures you'll see elsewhere. An unusually open, unshaded roof in San Francisco reaches about 1,931 hours, roughly 6% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,819 hrs/yr |
|---|---|
| Unshaded roof | 1,931 hrs/yr |
| Electricity rate (California avg) | 31.2¢/kWh |
| Installed cost assumed | $2.85/W |
| Panel size assumed | 400 W |
| Federal tax credit | 30% |
| Typical household usage | 10,800 kWh/yr |
| Power used as generated | 34% |
| Paid for exported power | 20% of retail |
| Rooftops sampled here | 6 |
| Google imagery from | 2024 |
Nearby cities
See all of California → statewide sunlight, rates, incentives and every city we've measured.
San Francisco solar questions
How many solar panels do I need in San Francisco?
About 18 panels for an average home. San Francisco roofs get 1,819 usable sun hours a year, so each 400W panel produces roughly 618 kWh annually.
Is solar worth it in San Francisco?
At 31.2¢/kWh and 1,819 sun hours, a typical system pays for itself in about 8.8 years and returns roughly $26,590 over 25 years. That is a solid return.
How much do solar panels cost in San Francisco?
A 7.2 kW system costs about $20,520 before incentives and $14,364 after the 30% federal tax credit. Prices vary by installer, roof complexity and equipment.
Worth reading before you buy
Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average California electricity rates. Not a quote and not financial advice. Your roof, usage, utility plan and local incentives will change these numbers — get real quotes before buying.