[Medium] How does the annual irradiance differ year-to-year in SLC?

[AdamRJensen]

Long-term irradiance is freely available from PVGIS and can easily be retrieved using the pvlib.iotools.get_pvgis_hourly function. Noticeably, PVGIS offers multiple irradiance databases; for North America, there are options of NSRDB PSM3 (satellite-derived) or ERA5 (reanalysis).

Method
Retrieve ERA5 reanalysis data for the period 2005-2020 and investigate the interannual variability. For example, generate a CDF and determine the mean, median, and 95th percentiles.

Follow-up questions

• What is the reduction in irradiance for the lowest year compared to the average (risk for a PV project)?
• How does the interannual variability compare to the sites reported by solargis?