AI for Science
EU rooftop solar could supply about 40% of electricity demand in a fully renewable 2050 scenario
In a 2026 paper in Nature Energy, researchers at the Joint Research Centre and the National Renewable Energy Centre mapped rooftop solar potential for 271 million buildings across the European Union. They used the European Digital Building Stock Model R2025, an open-access building-level database. The estimate puts total rooftop capacity at 2.3 terawatts peak, a measure of maximum power output. That breaks down as 1,822 gigawatts peak from residential buildings and 519 gigawatts peak from non-residential buildings. With current photovoltaic technology, which turns sunlight into electricity, the rooftops could produce 2,750 terawatt-hours of electricity a year. That is about 40 percent of demand in a 2050 scenario where all electricity comes from renewable sources.
What could rooftops deliver by 2030?
By 2030, more than half of buildings with floor area larger than 2,000 square metres could provide most of the remaining capacity for the 2030 target, with 355 gigawatts peak. Across member states, non-residential rooftops could cover 50 percent or more of their photovoltaic targets, and several could cover more than 95 percent.
How could the database be used?
The authors describe the building-level database as a practical tool for planners and researchers. It could help them study energy scenarios with high shares of renewable electricity.
Frequently asked questions
What did the study actually measure?
The study estimated potential rooftop solar capacity and yearly electricity output from a building-level model of 271 million buildings in the European Union. It did not report measured output from installed panels.
Does rooftop solar replace all electricity today?
No. The 40 percent figure applies to a modeled 2050 scenario with all renewable electricity, rather than to current demand.
Which rooftops matter most in the near term?
By 2030, more than half of buildings with floor area larger than 2,000 square metres could provide most of the remaining capacity for the 2030 target. Across member states, non-residential rooftops could cover at least half of photovoltaic targets, and several could cover more than 95 percent.
Limits and what's next
The study covers 271 million buildings in the European Union and relies on the European Digital Building Stock Model R2025. It estimates potential capacity with current photovoltaic technology and a modeled 2050 renewable scenario, rather than measured electricity from installed systems. The results estimate potential capacity rather than electricity already being generated. This is one study, and the abstract reports no independent replication of the estimates.
Source: Georgia Kakoulaki et al., “Mapping Europe’s rooftop photovoltaic potential with a building-level database,” Nature Energy, 2026.