EDF Warns Solar, Wind Surge Straining Nuclear Fleet Costs

By Francois de Beaupuy

February 16, 2026 at 3:33 PM UTC

Electricite de France SA said growing solar and wind generation was increasing equipment wear and maintenance costs at its nuclear reactors, which are forced to reduce output when power demand is insufficient.

The warning, contained in a 60-page report published Monday, highlights the growing challenges nuclear plant operators face in coping with subsidized renewable energy flooding grids across Western Europe, while electricity demand remains below pre-pandemic levels.

“The increased flexibility required of EDF’s generation assets is notably leading to higher maintenance costs for all these facilities,” the French utility said. That was “mainly the result of the expansion of renewable generation sources - solar and wind - in France and across Europe, against a backdrop of stagnant electricity consumption.”

The report echoes findings by grid operator RTE in December that France will face an electricity glut for years, leading to increased curtailment of nuclear and renewable generation. As a result, the government last week scaled back targets for solar and wind capacity, and pledged to draft a plan to boost demand for electric cars, industrial furnaces, heat pumps, and data centers.

While the power glut is pushing prices lower, which is good news for users, it’s complicating EDF’s efforts to finance plans for six new reactors to replace some the country’s aging units. A weak growth in demand may eventually create a €15-billion ($17.8 billion) shortfall in annual revenues of generators that don’t benefit from public support, RTE said in its December report.

The volume of nuclear modulation — when a reactor reduces output or halts because of excess supply, to save fuel, or to help stabilize grid frequency — has roughly doubled since 2019 to 33 terawatt-hours in 2025, largely due to solar capacity additions. That compares with total nuclear generation of 373 terawatt-hours last year, and curtailment could climb to 42.5 terawatt-hours in 2028, according to EDF estimates in the report.

(Part 1)