Solargis API Long Term Averages (LTA)

WS API request parameters (represented as XML elements and attributes) are formally described by XML Schema Definition documents (XSD). To validate XML files we provide two endpoint variants:

• SOAP
• REST

Price is qouted based on number of requests and type of use. Typicaly, licence to access API is valid for one year. Authentication is based on API key registered with the customer.

• GHI - Monthly and annual long-term averages Global Horizontal Irradiation [kWh/m2]
• DIF - Monthly and annual long-term averages of Diffuse Horizontal Irradiation [kWh/m2]
• GTI - Monthly and annual long-term averages of Global Tilted Irradiation [kWh/m2], available for selected or optimum tilt and azimuth
• DNI - Average yearly, monthly or daily sum of direct normal irradiation [kWh/m2]
• TEMP - Monthly and annual long-term averages of Air Temperature at 2m [°C]
• PVOUT - Monthly and annual long-term averages of photovoltaic electricity output [kWh] for the PV system specified in the input
• PR - Monthly and annual long-term averages of Performance Ratio [%]
• TERRAIN – elevation above sea level and terrain horizon
• RH - Average monthly and annual relative humidity at 2 m above ground [%]
• PWAT - Average monthly and annual values of precipitable water [kg/m2]
• PREC - Average yearly and monthly sums of precipitation (rainfall) [mm]
• WS - Average yearly, monthly and daily wind speed at 10 m above ground [m/s]
• ALB - Surface albedo, fraction of solar irradiance reflected by surface. Ratio of upwelling to downwelling (GHI) radiative fluxes at the surface 

Meteo parameters

• GHI - Global Horizontal Irradiance/Irradiation
• GTI - Global Tilted (in-plane) Irradiance/Irradiation
• DIF - Diffuse Horizontal Irradiance/Irradiation
• DNI - Average yearly, monthly or daily sum of direct normal irradiation [kWh/m2]
• PREC - Average yearly and monthly sums of precipitation (rainfall) [mm]
• WS - Average yearly, monthly and daily wind speed at 10 m above ground [m/s]
• TEMP - Air temperature at 2 m
• RH - Relative humidity at 2 m above ground [%]
• PWAT - Precipitable water [kg/m2]

Simulation method

• PVOUT – calculation of potential electricity energy output from customer defined PV system
• PR - Performance ratio

Geographic parameters

• TERRAIN – elevation above sea level and terrain horizon
• ALB - Surface albedo 

Temporal summarization

  Long-term averages

• monthly
• yearly

The temporal coverage of Solargis irradiation data varies by region due to satellite imagery availability. With few exceptions, the coverage spans from the 1990s/2000s to the present time. Depending on the region, the long-term averages are calculated for a period from 1994/1999/2005/2007/2018 to 2022. Please, refer to the map above for specific start year.

The long-term average of air-temperature is calculated for a period 1994-2022 globally.