Floating solar : France is multiplying power plants on its lakes and dams

On a former body of water in Vaucluse, in Piolenc, tens of thousands of solar panels have floated since 2019. Seven years later, this French first in floating solar has spawned imitators : France now builds, lake after lake and dam after dam, a park of photovoltaic plants placed on water rather than on agricultural land.

From O'MEGA1 to Îlots Blandin, a sector that is scaling up

It all started with O'MEGA1, commissioned in October 2019 by Akuo Energy on a former aggregate extraction site in Piolenc. With its 47,000 panels spread over 17 hectares, it long stood out as an exception before being expanded to 22 megawatt-peak (MWp) in summer 2022.

Since then, projects have followed one another. EDF commissioned Lazer in June 2023 in the Hautes-Alpes, a 20 MWp floating plant with more than 50,000 panels installed on a hydroelectric dam. Then, in June 2025, the Îlots Blandin plant in Haute-Marne took over with more than 135,000 panels over 127 hectares, for a capacity of 74.3 MWp: it is today presented as the largest floating solar installation in Europe.

Cheylas, the next major project in Isère

The momentum continues in 2026. EDF is preparing a new large-scale project called Cheylas, in Isère, whose major works are to start at the beginning of the year, with commissioning targeted for summer 2027. This timetable confirms the acceleration of a technological sector that, less than ten years ago, simply did not exist in France, driven by companies such as Akuo Energy or EDF.

• O'MEGA1 (Vaucluse) : 22 MWp, 47,000 panels, commissioned 2019
• Lazer (Hautes-Alpes) : 20 MWp, more than 50,000 panels, commissioned 2023
• Îlots Blandin (Haute-Marne) : 74.3 MWp, more than 135,000 panels, commissioned 2025
• Cheylas (Isère) : construction launched early 2026, commissioning targeted mid-2027

Why install panels on water ?

The interest of floating solar lies first in the land resource it helps save : industrial bodies of water, former gravel pits or dam reservoirs do not compete with agricultural land or terrestrial natural spaces, a strong argument at a time when soil sealing remains a constant concern in France.

Technically, water also provides a natural cooling effect for the panels, which slightly improves their efficiency compared with conventional ground-mounted installations, while the partial coverage of the water body limits evaporation.

An impact on biodiversity under scrutiny

The question of aquatic ecosystems remains. At the pioneering O'MEGA1 site, an annual ecological monitoring of fauna and flora has been carried out since commissioning, and the available results report a generally positive impact on local biodiversity. This control of impacts on aquatic environments should remain a determining criterion in the assessment of future projects, as the sector scales up.

Frequently asked questions

What is floating solar ?

These are photovoltaic plants installed on floats, on the surface of industrial bodies of water, former gravel pits or dam reservoirs, rather than on agricultural or natural land.

What is the largest floating solar plant in France ?

Îlots Blandin, in Haute-Marne, commissioned in June 2025 with a capacity of 74.3 MWp, is presented as the largest floating installation in Europe.

Does floating solar have an impact on fauna and flora ?

The ecological monitoring carried out at the O'MEGA1 site since 2019 shows a generally positive impact on local biodiversity, but management of this impact remains closely monitored for each new project.

Sources

• Akuo Energy — Floating solar
• Connaissance des Énergies — O'MEGA1, the largest floating power plant in Europe
• Actualités News Environnement — Floating solar: Is France catching up?

This article was written with the help of artificial intelligence. Editorial policy