Paris leads EU capitals for rooftop solar generation potential

A research team from Athens’ Institute for Environmental Research and Sustainable Development and the National and Kapodistrian University developed a framework using urban datasets, climatological records from 2008 to 2023, and standardized PV simulations to assess rooftop solar potential across all 27 EU capital cities. The study, published in the journal Energy, highlights that while rooftop PV can make a substantial contribution to urban electricity supply everywhere, its effectiveness varies widely due to differences in urban form, weather, and local demand patterns.

The analysis ranked Paris, France, as having the largest exploitable rooftop area for PV at 72.2 km², followed by Berlin, Germany (52.4 km²), and Warsaw, Poland (51.6 km²). At the lower end, Nicosia, Cyprus (6.2 km²), Ljubljana, Slovenia (5.6 km²), and Valletta, Malta (2.6 km²) had the smallest available rooftop space. Annual generation potential mirrored this ranking, with Paris leading at 3.810 TWh, followed by Budapest (2.548 TWh), Warsaw (2.506 TWh), and Rome (2.035 TWh).

The study identified cloud cover as the primary source of solar energy losses across Europe, with shading, clouds, and aerosols explaining variations even among cities with similar rooftop resources. Researchers incorporated three modification factors into their framework to account for urban shading, cloud cover, and aerosol shading, providing a more accurate assessment of real-world potential.

While rooftop PV could cover up to around 35% of total electricity demand in the best-performing cities, the study emphasizes it cannot serve as a standalone solution. Achieving climate-neutral cities will require storage, flexibility solutions, grid upgrades, and complementary renewable technologies, with deployment strategies tailored to local urban realities rather than uniform policies.