EO Capability Benefits
Solar radiation is important for siting solar farms, as it informs energy yield estimations. Similarly, the Solar Potential of Buildings and energy-efficient building design rely on this variable. In agriculture, crop yield forecasting and evapotranspiration analysis require an accurate understanding of solar radiation. Finally, our climate and atmospheric dynamics are influenced by the sun’s radiation at a fundamental level.
EO Capability Description
Solar radiation is an umbrella term for a range of measurements and types of solar energy reaching the Earth. Solar irradiance, indicated in W/m², is the power per unit area received from the Sun in the form of electromagnetic radiation. Connected to this is solar insolation representing the total amount of solar energy received over a given period of time per unit area, commonly measured in kWh/m²/day (sometimes also called average irradiation). Different temporal units can be used, e.g. to derive monthly or annual averages.
Approaches typically combine data from geostationary (e.g. GOES, Meteosat) and polar-orbiting satellites (e.g. MODIS) with high temporal resolution, with sophisticated modelling techniques. Clear sky models are used to estimate solar surface irradiance under cloudless conditions, accounting for the Earth-Sun distance as well as the atmosphere’s composition (e.g. aerosols, water vapor and ozone) and the path length of radiation passing through the atmosphere depending on the Sun’s position. More complex models also account for local atmospheric variability, such as that caused by air pollution.
As Cloud Cover affects the amount of radiation reaching the Earth’s surface, satellite imagery is used to calculate the effective cloud albedo relative to clear-sky conditions, thus enabling all-sky irradiance to be estimated. This approach provides data for regions lacking ground-based measurements.
As higher altitudes receive more intense irradiance, Digital Elevation Models are also used to account for the effects of elevation on solar irradiance.
Indicative Cost Range Details
Various solar radiation-related global datasets at 0.05 degrees spatial resolution are available freely through EUMETSAT’s Satellite Application Facility on Climate Monitoring (CM SAF). Specialised companies offering end-to-end solutions tend to follow a subscription model.
