The Character and Variability of Solar Irradiance across the U.S. Pacific Northwest

Abstract:

The northwestern United States is not typically thought of as a promising location for solar energy production because of its high latitude and frequent cloud cover. However, conditions vary widely across this region, and even those areas prone to extended cloudiness have very high solar potential during the summer when days are clear and as much as 16 hours long. Given that this area is also somewhat isolated from the rest of the US electrical transmission grid, an assessment of the character of the area's solar resource is warranted. In this talk, we present results of an analysis of irradiance data from five sites spread across the northwestern US from western Oregon to southwestern Montana. The availability and variability of solar irradiance at each location is described over a range of temporal scales. Observed differences are related to local weather patterns, which vary with geographic location. The relationships among the irradiance time series measured at the individual sites are also examined, with consideration of potential smoothing of overall output that might be achieved if solar power plants were built in multiple locations.

* Data provided courtesy of the University of Oregon Solar Radiation Monitoring Laboratory