The European Union's expansion of solar energy is on track for its first annual downturn in more than a decade, industry data showed on Thursday, as some governments reduce subsidies for rooftop solar panels, Reuters reported.

The trend reflects shifting political priorities in Europe as some member countries have scaled back green measures or support for clean energy from budgets stretched by spending on defence and local industries.

The EU is on track to install 64.2 gigawatts of new solar energy capacity in 2025, a 1.4% decrease compared with the 65.1GW installed last year, industry association SolarPower Europe said.

The drop would mark the first time since 2015 that the growth of Europe's solar market has slowed year on year, denting an area of fast progress in Europe's shift to clean energy. Solar capacity growth soared by 51% in 2023, although last year growth had already slowed to 3%.

Last month, solar generated 22% of total EU electricity, making it the EU's largest single source of power generation that month.

But current deployment rates now indicate the EU will fall short, by about 27GW, of the 750GW of solar capacity which SolarPower Europe said is needed by 2030 for the EU's climate targets and plans to phase out Russian energy.

The main cause of the downturn is fewer residential rooftop solar panel installations - a sector that is set to make up 15% of total new capacity this year, halving the roughly 30% share it held over 2020 to 2023.

Germany and France are among the countries reducing their feed-in tariff payments for rooftop solar energy, while the Netherlands is also reducing support for households that export their excess solar power to the grid.