Solar energy in Philadelphia, United States
Average irradiation 4.06 kWh/m²/day · ~1186 kWh per kWp per year
Monthly solar irradiation & temperature in Philadelphia (NASA POWER)
| Month | Irradiation (kWh/m²/day) | Avg temp (°C) | Est. production per kWp (kWh) |
|---|---|---|---|
| Jan | 2.02 | -1.0 | 49 |
| Feb | 2.90 | 0.1 | 71 |
| Mar | 3.83 | 4.5 | 93 |
| Apr | 4.99 | 10.8 | 121 |
| May | 5.57 | 16.5 | 136 |
| Jun | 6.17 | 21.6 | 150 |
| Jul | 6.17 | 24.6 | 150 |
| Aug | 5.40 | 24.0 | 131 |
| Sep | 4.42 | 20.4 | 107 |
| Oct | 3.18 | 13.5 | 77 |
| Nov | 2.33 | 7.1 | 57 |
| Dec | 1.75 | 2.0 | 43 |
Solar potential of Philadelphia explained
Philadelphia receives an average of 4.06 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 1186 kWh of electricity per year here, assuming a well-oriented system with a typical 80% performance ratio. This is a solid mid-range solar resource: production is meaningful year-round, though winter output drops noticeably.
Frequently asked questions
Is solar worth it in Philadelphia?
With 4.06 kWh/m²/day of average irradiation, a 1 kWp system in Philadelphia produces roughly 1186 kWh per year. That is a good solar resource; with current panel prices most systems pay back well within their lifetime.
How much electricity would a 5 kW system produce in Philadelphia?
Approximately 6,000 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
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