Estimating energy output from solar panels

As greenhouse gas emissions continue to drive global warming, implementing alternative energy sources is becoming increasingly important. In the 2023 Synthesis Report on Climate Change, the United Nations’ Intergovernmental Panel on Climate Change highlighted solar energy as a cost-effective mitigation measure, noting that in the period from 2010 to 2019, there has been an 85% decrease in the global cost per unit of energy produced by photovoltaics.

But knowing whether the amount of energy produced by solar panels at a specific location would offset their cost can be tricky to determine. Recently, Dr Ana Martinez of the European Commission’s Joint Research Centre and Dr Christine Traeger-Chatterjee of EUMETSAT’s User Support & Climate Services published a case study about a free online tool that makes it much easier to figure this out.

The Photovoltaic Geographic Information System (PVGIS) uses solar radiation data to estimate how much energy solar panels installed at a given location would produce. The tool allows people to choose nearly any place on land throughout the world and a wealth of information will be presented, for example, monthly, daily, and hourly data for different types of solar panels as well as the long-term average energy output of a photovoltaic system installed at a particular location.

Depending on the region of the world, PVGIS receives solar radiation data from different sources. For Europe, Africa, much of Asia, and eastern South America, the observations come from instruments on board EUMETSAT’s Meteosat satellites and have been compiled by the EUMETSAT Climate Monitoring Satellite Application Facility (CM SAF).

“When the PVGIS was first introduced, it only included data from ground stations, so although the solar radiation in some areas could be estimated very accurately, for other areas, such as those between ground stations, the measurements had to be interpolated,” said Traeger-Chatterjee.

“This made the accuracy very irregular, especially in areas with complex terrain. But now, thanks to the inclusion of satellite data, this has improved a lot.”

As better inputs for the PVGIS draw an increasing number of users – last year more than 6 million unique users across the globe accessed the tool – the responsibility to continue to provide the most accurate data also grows. While the current data for the region spanning Europe, Africa, much of Asia, and eastern South America come from the period spanning 2005 to 2020, Traeger-Chatterjee stresses that providing the PVGIS with the newest data is ongoing.

“It is important that this database is kept up to date, which requires us to keep updating the solar radiation data record,” said Traeger-Chatterjee.

“This is where the new satellites play such an important role. Satellites including the next generation of Meteosat satellites, Meteosat Third Generation, will enable us not only to continue to provide data to users of the PVGIS for many years to come but to further improve its accuracy as time goes by.”

To find out more, check out the case study “Information System for global PV potential uses CM SAF data”.

Author:

Sarah Puschmann