Électricité de France (EDF), Europe’s largest power utility, says about 90% of its activity depends on water—an exposure that climate change is turning into an operational risk for both its nuclear plants and hydropower dams.
The company’s nuclear fleet relies on river water to cool reactors, while hydropower output depends on steady river flows. But climate projections point to more frequent droughts, hotter rivers, and lower flows—conditions that can force nuclear units to scale back or shut down under environmental rules, and that directly cut hydropower generation.
EDF has launched a long-range nuclear adaptation program running through 2100, known as ADAPT. The plan goes beyond engineering fixes, folding in worker health and working conditions—down to equipment such as ventilated jackets for staff operating in overheated environments. Catherine Halbwachs, EDF’s CSR director for its thermal nuclear fleet and the ADAPT project lead, framed the broader risk during the Covid crisis: “How do you run a nuclear power plant without employees, if they are confined and if daycare centers for their children are closed?”
$1.1 billion already spent—and a projected 1.4% hit to nuclear availability
The cost of climate adaptation is estimated at about €1 billion (about $1.1 billion) for the period already elapsed, according to Ouest-France. EDF has described that figure as “modest” given the industrial stakes.
Internally, EDF’s modeling points to a more persistent drag: climate change could cause average unavailability equal to 1.4% of its nuclear production target, according to Le Monde. For a fleet that produced 373 terawatt-hours (TWh) of nuclear electricity in France in 2025—out of 515 TWh total generation across all sources—that percentage represents a meaningful loss of available capacity.
Cooling is at the center of the challenge. Most French nuclear plants sit along major rivers—the Loire, Rhône, Garonne, and Seine—drawing water for cooling and discharging it back at a higher temperature. When rivers run too warm or too low, regulations can restrict operations or require reactors to shut down. That has happened during heat waves in 2003 and 2019, and EDF faces the prospect of more frequent constraints as extreme heat becomes more common.
Inside ADAPT: ventilated jackets and planning for 122°F summers
EDF is modeling summer conditions reaching 50°C (about 122°F) in parts of France within the next few decades. In that scenario, resilience isn’t just about pipes and turbines. It also depends on whether employees can work safely in industrial buildings without air conditioning, get enough rest during prolonged heat, and keep maintenance schedules on track.
The company says it also drew lessons from the Covid pandemic about dependence on the surrounding community. A nuclear plant does not operate in isolation: it relies on roads to deliver parts, on schools and childcare so workers’ families can remain nearby, and on local businesses that sustain daily life around the sites. Halbwachs’ point, as EDF frames it, is that the pandemic’s systemic shock sharpened the company’s awareness that it cannot manage resilience on its own.
Hydropower is already showing the impact of reduced water inflows. In 2025, EDF produced 37.9 TWh of net hydropower in France, down from 47.8 TWh in 2024—a drop of nearly 10 TWh in a single year. EDF links that volatility to hydrological variability that warming is amplifying, making planning increasingly uncertain.
Strong 2025 results, but water remains the variable EDF can’t control
EDF reported solid full-year 2025 results: €8.4 billion (about $9.1 billion) in net income, €9.6 billion (about $10.4 billion) in operating cash flow, and a credit rating upgrade by S&P to BBB+ stable in January 2026. CEO Bernard Fontana set “safety, security, health” as the group’s three priorities, promising customers “competitive, sovereign and low-carbon electricity.”
The company proposed a €1 billion (about $1.1 billion) dividend for 2025, subject to approval at a shareholders meeting convened after the board’s February 19, 2026 decision—an expression of confidence in current financial balances.
But EDF’s climate vulnerability sits alongside its climate role. The company says 95% of its electricity is produced from low-carbon sources, with a carbon intensity of 26.5 gCO2/kWh in 2025, contributing to the decarbonization of Europe’s power system. The paradox, EDF acknowledges, is that this low-carbon output is itself exposed to the climate impacts it helps limit.
And the roughly €1 billion (about $1.1 billion) already spent on adaptation does not indicate what comes next. EDF still faces the prospect of structural modifications to facilities designed 40 to 50 years ago—built for a climate that no longer exists.
