Solar radiation atlas

The Solar Atlas is a joint initiative of Latvia, Poland, Estonia and Lithuania. Radiation maps are based on satellite data provided by EUMETSAT CM SAF SARAH data set for period 1991-2014. Read more from EUMETSAT web page.

Comparison of satellite data with ground-based observations of radiation data from Latvia, Lithuania and Estonia show that the average monthly solar surface irradiance and direct irradiance values of satellite data are somewhat lower (6-9 W/m2) than those measured in meteorological stations. The difference in direct normalised irradiance is 13-18 W/m². Solar Atlas features information on the general direct and indirect solar irradiation to a perpendicular surface (W/m²).

Statistical data features the average, minimum, maximum, standard deviation (distribution of average values), as well as deviation from the average of 1991-2014 in a specific month, season or year.

Differently from land-based measurements at meteorological stations, satellite data provides information on the solar irradiation in the entire territory rather a specific point. Satellite data provides detailed information on the geographic distribution of the intensity of solar irradiation and differences in various places.