Oregon has a rainy reputation, but did you know that solar energy is Oregon’s most abundant renewable energy resource? Oregon has a good solar resource that can be put to work.

West of the Cascade mountain range, our sunny summers offset our cloudy winters, giving Portland and Eugene as much annual solar energy as the national average.

Communities east of the Cascades get as much sun each year as Miami!

Germany is installing more new solar energy systems per capita in the world than any other country, yet its capital, Berlin, receives less sun than the cloudiest location in Oregon, near Astoria.

The chart below shows how much sun we receive in Oregon. “Peak sun hours” are the number of equivalent hours of full sun received in a day, averaged throughout the year. The chart also shows how much electricity each Watt_DC of a photovoltaic system can be expected to produce each year in Oregon. The data are based on output from the PVWatts calculator with assumed system efficiency of 80% converting from DC to AC power. Units are kilowatt-hours per year per rated peak watt of the PV array.

Other cities for comparison:

When designing a solar energy system, remember that Oregon’s solar resource is seasonal. A summer day sees about 3 times as much sun as a winter day.

To learn more about Oregon’s solar resource, visit University of Oregon’s Solar Radiation Monitoring Laboratory, which has been measuring solar radiation in the Pacific Northwest for more than 30 years.