EU rooftops could be huge source of solar power, study finds

EU rooftops held huge untapped potential for solar-energy generation, according to a new study, which created a database of 271 million structures in Europe.

The research, by the European Commission's Joint Research Centre (JRC), was released earlier this week (12 January).

It found most EU states – except Cyprus, Finland, and Sweden – could produce more than 50 percent of their 2024 energy demand with rooftop solar panels. 

France and Germany, the countries with the highest rooftop potential, could produce 80 percent of their current energy demands.

Greece, Hungary, and Romania could produce more energy than they currently consume. 

Rooftop estimate

To estimate total rooftop potential across the EU, the researchers took an individual building-level approach.

They created a pan-European Digital Building Stock Model, which is an open database, using satellite data, to estimate the size and function (residential or non-residential) of 271 million structures, finding a total footprint area of approximately 37,370 km2. 

The database is meant to help other scientists in their own energy research. 

From the total area, the scientists estimated that 10,000 km2 of rooftop area was suitable for solar energy capture, with a potential capacity of 2.3 terawatts, producing 2,750 terawatt hours per year.

And based on their calculations, the researchers said almost all EU member states had the potential to generate 40 gigawatts of solar energy each. 

The researchers estimated that EU rooftops, with current solar technology, were capable of producing 2.3 terawatts of solar energy (a terawatt is 1,000 gigawatts).

For comparison, the EU had 406 gigawatts of solar generation capacity in 2025.

Solar rising

Solar is an increasing part of the EU's energy production, with the commission's statistical office, Eurostat, finding that, in the month of June 2025, the sun was the main source of electricity for the bloc, generating 22 percent of the total electricity mix.

The EU is also aiming to produce at least 700 gigawatts of solar energy by 2030.

However, the researchers pointed out that, as of today, only 10 percent of European rooftops had solar systems.  

The commission is emphasising adding solar to buildings, with the 2024 update of the Energy Performance of Buildings Directive adding solar installation requirements for new constructions and deadlines for updating old ones by 2030.

Member states have until the end of May 2026 to transpose this directive into their national laws. 

As the JRC researchers wrote, "the results show that already for 2030 over 50 percent of the PV [photovoltaic] capacity foreseen in the individual plans of the EU countries could be met just from PV on non-residential rooftops in most cases."

The researchers said that even partial utilisation of rooftop solar potential could substantially contribute to meeting renewable energy policy requirements, such as the REPowerEU policy, or 2050 net-zero plans. 

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