Solar energy in San Francisco, USA
Average irradiation 4.73 kWh/m²/day · ~1381 kWh per kWp per year
Monthly solar irradiation & temperature in San Francisco (NASA POWER)
| Month | Irradiation (kWh/m²/day) | Avg temp (°C) | Est. production per kWp (kWh) |
|---|---|---|---|
| Jan | 2.45 | 9.3 | 60 |
| Feb | 3.36 | 10.3 | 82 |
| Mar | 4.62 | 11.4 | 112 |
| Apr | 5.99 | 12.2 | 146 |
| May | 6.71 | 14.0 | 163 |
| Jun | 7.28 | 16.0 | 177 |
| Jul | 6.53 | 16.8 | 159 |
| Aug | 5.82 | 17.3 | 142 |
| Sep | 5.12 | 17.6 | 124 |
| Oct | 3.95 | 15.8 | 96 |
| Nov | 2.81 | 12.4 | 68 |
| Dec | 2.13 | 9.6 | 52 |
Solar potential of San Francisco explained
San Francisco receives an average of 4.73 kilowatt-hours of solar energy per square metre per day, measured over four decades of satellite observation. In practical terms, every kilowatt-peak of installed PV capacity yields about 1381 kWh of electricity per year here, assuming a well-oriented system with a typical 80% performance ratio. This places San Francisco among the stronger solar locations globally — comparable to southern Spain or California.
Frequently asked questions
Is solar worth it in San Francisco?
With 4.73 kWh/m²/day of average irradiation, a 1 kWp system in San Francisco produces roughly 1381 kWh per year. That is an excellent solar resource — payback periods are typically among the shortest worldwide.
How much electricity would a 5 kW system produce in San Francisco?
Approximately 7,000 kWh per year — enough to cover a large share of a typical household's consumption.
What data is this based on?
Long-term satellite observations from NASA POWER (1981–present) and the PVGIS SARAH3 database, assuming a performance ratio of 80%.
Compare with nearby cities
New York (4) · Los Angeles (5.4) · Phoenix (5.9) · Houston (4.7) · Miami (5.1) · Denver (5) · all cities →