Solar energy set a historic milestone in June 2025, becoming the leading source of electricity in OECD Europe, according to the International Energy Agency (IEA). Solar contributed 19.9 percent (53.9 TWh) of the region’s net electricity generation, while the combined share of solar and wind reached a record 35.8 percent (97.0 TWh) of total output.
OECD Electricity Generation Rises 1.4 percent Year-on-Year
Across the OECD, total net electricity generation rose 1.4 percent year-on-year to 922.6 TWh. Fossil fuels supplied 416.8 TWh (45.2 percent), renewables 358.6 TWh (38.9 percent), and nuclear 143.2 TWh (15.5 percent). Electricity from fossil fuels dipped 1.8 percent y-o-y, led by declines in natural gas (-2.1 percent, or -5.5 TWh) and coal (-1.3 percent, or -1.9 TWh).
Solar and Wind Drive Renewable Surge
Renewable generation climbed 7.3 percent y-o-y (+24.4 TWh), fueled by a 24.7 percent jump in solar output (+23.5 TWh) across the OECD. Total solar generation reached 118.7 TWh (12.9 percent of total generation). The OECD Americas saw the largest absolute increase, with the United States driving a 32.3 percent gain (+10.0 TWh). OECD Europe’s solar production surged 25.0 percent (+10.8 TWh), with Lithuania posting an exceptional 303 percent increase (+0.4 TWh).
Wind generation also grew 8.8 percent y-o-y (+7.3 TWh) to 89.7 TWh (9.7 percent of total generation), while hydropower output slipped 2.7 percent (-3.8 TWh) to 135.2 TWh (13.3 percent of total generation), largely due to a 5.3 percent decline in OECD Europe (-6.8 TWh).
Nuclear Output Declines Slightly
OECD nuclear generation decreased 2.3 percent y-o-y (-3.4 TWh), with output down 2.7 percent in both OECD Europe and the Americas, while Asia Oceania remained steady.
Key Takeaway for Energy Transition
The data highlights a clear shift toward solar and wind power as the dominant forces in OECD electricity generation. June 2025 marks a turning point where clean energy sources outpaced fossil fuels in growth, reinforcing the transition to a low-carbon energy future and signaling strong opportunities for renewable investments and infrastructure development.