France has transformed a former gravel-quarry site in Haute-Marne into Europe’s largest floating solar farm, covering 127 hectares and featuring 135,000 photovoltaic modules. The Les Ilots Blandin project, located near Perthes, began operating in June 2025, using former quarry basins to generate renewable electricity.
With a total capacity of 74.3 MW, the installation is expected to generate enough electricity to supply around 37,000 people annually while avoiding significant carbon dioxide emissions. Q ENERGY and Grand Est Development International provided details about the project.
How France Turned 127 Hectares of Gravel Pits into a Floating Solar Farm
The project was built across six unused basins created by gravel extraction at the former Blandin quarry site. According to Grand Est Development International, the 127-hectare site was repurposed after quarrying activities ended, avoiding the need to develop an entirely new area of land for the solar installation. The organisation describes the project as Europe’s largest floating solar park.
Q ENERGY began developing the project in 2019, with the aim of using abandoned industrial basins to generate renewable energy. The company identified the former gravel pits as suitable locations because of their solar potential and limited land-use conflicts. Quarry operations were scheduled to end in 2020.
The location also allowed the project to utilise water surfaces already created by industrial activity. Instead of installing all the solar panels on open ground, much of the facility sits on floating structures across the former quarry basins.
What Makes the Les Ilots Blandin Project So Large
The scale of the project is reflected in its more than 135,000 photovoltaic modules, installed on floating platforms developed in France. Grand Est Development International estimates that around 100 people were involved in the project, while construction took 15 months.
The solar panels cover 45.5 hectares, although the overall project extends across 127 hectares. According to Balkan Green Energy News, 72.3 MW of the plant’s capacity is installed on floating platforms, while another 2 MW comes from a ground-mounted section. The six floating platforms range in capacity from 8 MW to 17 MW each.
The ground-mounted section was included for practical reasons. Q ENERGY said the 2 MW system was incorporated into the project to improve overall energy output and economic performance.
Electricity Generation Capacity of the Floating Solar Farm
The plant has a total capacity of 74.3 MWp. According to Q ENERGY, it can generate enough renewable electricity annually to supply approximately 37,000 people and is expected to prevent 18,000 tonnes of carbon dioxide emissions each year.
The electricity generated gives the former industrial site a new purpose. Once associated with gravel extraction, the area is now being used to produce renewable power while making use of existing water basins.
The installation was officially inaugurated on 20 June 2025. Q ENERGY said construction began in September 2023 following more than five years of planning, with the plant reaching full commissioning in June 2025.
Why Floating Solar Was Chosen for the Former Quarries
Floating solar remains an emerging technology in France, particularly in the country’s northern regions. Q ENERGY said these projects can utilise areas where land-use conflicts are limited, although their financial viability remains a significant challenge.
Floating installations generally cost more to construct and maintain than conventional ground-mounted solar farms. According to Balkan Green Energy News, they must also compete directly with ground-based solar projects in France’s public tender system rather than benefiting from a separate tender process.
These challenges made the design and economics of Les Ilots Blandin particularly important. Q ENERGY said several configurations were evaluated before the final arrangement was selected, including the addition of the 2 MW ground-mounted section.
Companies Involved in Bringing the Project into Operation
Les Ilots Blandin was developed through a partnership involving several companies. Q ENERGY initiated the project, while Ciel & Terre supplied and installed the floating structures, solar modules and inverters. Perpetum handled the electrical infrastructure and construction of the ground-mounted array, while Solutions30 was responsible for cabling, grid connection and overall commissioning.
Construction funding was secured in September 2024, with more than €50 million raised through Crédit Agricole Transitions & Énergies and Bpifrance. In early 2025, Spanish renewable energy company Velto Renewables acquired a 50% stake and became a long-term owner of the asset.
