Solar energy in Portland, United States
Average irradiation 3.66 kWh/m²/day · ~1069 kWh per kWp per year
Monthly solar irradiation & temperature in Portland (NASA POWER)
| Month | Irradiation (kWh/m²/day) | Avg temp (°C) | Est. production per kWp (kWh) |
|---|---|---|---|
| Jan | 1.20 | 3.5 | 29 |
| Feb | 2.07 | 4.1 | 50 |
| Mar | 2.99 | 6.3 | 73 |
| Apr | 4.30 | 8.5 | 105 |
| May | 5.44 | 12.2 | 132 |
| Jun | 6.00 | 14.9 | 146 |
| Jul | 6.82 | 18.9 | 166 |
| Aug | 5.82 | 19.7 | 141 |
| Sep | 4.30 | 16.5 | 105 |
| Oct | 2.59 | 10.9 | 63 |
| Nov | 1.40 | 6.1 | 34 |
| Dec | 0.98 | 3.1 | 24 |
Solar potential of Portland explained
Portland receives an average of 3.66 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 1069 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 Portland?
With 3.66 kWh/m²/day of average irradiation, a 1 kWp system in Portland produces roughly 1069 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 Portland?
Approximately 5,000 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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