Used sources

Used sources


Solar energy is one of the environmentally sustainable resources for producing electricity using photovoltaic systems. The main input data used in the planning process is solar radiation. We have developed a solar radiation database from climatologic data homogenized for Europe and available in the European Solar Radiation Atlas, using the r.sun model and the interpolation techniques s.vol.rst and



The Forecast Data API grew out of the original weather data API we built for Dark Sky. The Dark Sky API was designed to be very specialized for hyperlocal forecasting, and therefore was very tightly coupled to its data sources. As we tried to expand its scope, we found that cramming other data sources into it was rather like fitting a square peg into a round hole; in the end, we decided to rebuild the API from scratch.

Dark Sky Blog


Weather Underground has challenged the conventions around how weather information is shared with the public since 1993. We're immensely proud of the unique products that our community and meteorologists have created to improve people's access to meaningful weather data from around the globe. As the Internet's 1st weather service, we consider ourselves pioneers within our field and we're constantly seeking new data sets and the next technologies that will help us share more data with more people.

About Wunderground


Our mission is to provide a global geospatial platform which is affordable to users and enables them to operate effortlessly with Earth Observation data like satellite imagery, weather data, and similar data sources. With our platform you can easily build new data-driven products for agriculture, logistics, retail, transportation, and many others.

About OpenWeatherMap


Founded with the goal of transforming how businesses worldwide interact with environmental phenomena, AerisWeather enables customers to harness the dynamic power of weather data and imagery in their products, services, and business intelligence tools. Leading with a developer-first mentality - “by developers, for developers”, AerisWeather’s API and Mapping Platform (AMP) are easily integrated into customers’ applications with the help of an extensive documentation library, SDKs, and step-by-step wizards. Coupling these technical resources with hands-on engineering and business support, AerisWeather has become the preferred data source and trusted partner to companies around the world.

About AerisWeather

Deutscher Wetterdienst

The Deutscher Wetterdienst is a public institution with partial legal capacity under the Federal Ministry of Transport and Digital Infrastructure. Germany's National Meteorological Service, the Deutscher Wetterdienst (DWD), is responsible for meeting meteorological requirements arising from all areas of economy and society in Germany.

DWD - About us

Norwegian Meteorological Institute

The Norwegian Meteorological Institute has a free and open data policy. We want the greatest possible use, dissemination and further processing of our material for the benefit of society.

Norwegian Meteorological Institute


From PVGIS the daily radiation data are used to calculate the forecast for a specific plane defined by declination and azimuth at a specific location in Europe. From DarkSky and Wunderground the combined cloud coverages forecast and the temperatures will be used for the solar production forecast.