SDG&E Solar Potential Index Daily forecast of the amount of solar irradiance across thirteen forecast zones within the SDG&E service territory, given as a fraction of the peak solar irradiance at solar noon on the summer solstice under clear-sky conditions. Data and Resources ArchiveCSV Explore Preview Download solar irradiance Additional Info Field Value Last Updated May 3, 2021, 18:15 (UTC) Created April 14, 2021, 23:24 (UTC)