The Wedding Hall of the Town Hall of Achères hosted a public meeting on Wednesday, October 14, 2026, bringing together many residents to discover the 'La Grande Arche Solaire' photovoltaic park project. Organized by the City of Achères, the mixed-economy company SIPEnR, and Énergie Partagée, this gathering aimed to present the characteristics of the future installation and the possibilities for citizen participation.
The 'La Grande Arche Solaire' project aims to redevelop a former quarry, exploited between 2009 and 2024. Located on flood-prone and non-buildable land, this former quarry presented significant limitations for reuse. The installation of a photovoltaic farm on this site thus seeks to enhance its value by dedicating it to renewable electricity production, in an ecological approach that is more relevant than ever.
This initiative is part of a municipal commitment made over several years. An initial public consultation was held in the autumn of 2023, before the City entered into a partnership with the mixed-economy company SIPEnR.
The future installation is expected to reach a capacity of 16 megawatt-peak (MWc), with an estimated annual production of over 17 gigawatt-hours (GWh). This electricity output is equivalent to 58% of Achères' residential electricity consumption. The electricity produced will be injected into the public distribution network, thus contributing to renewable energy production. The minimum planned operating period for the park is 30 years.
Environmental studies conducted by ecologists and landscape architects have helped adapt the park's layout. Several measures are planned to limit its impact: maintaining about one-third of the site as grassland, including a 5.2-hectare area preserved in the center; a setback of at least 15 meters from the departmental road, accompanied by hedge plantings; a distance of 50 meters from the wooded area; and avoiding the most constrained sectors regarding flood risk. Photomontages have also been created from various viewpoints to study the project's landscape integration.
The 'La Grande Arche Solaire' project is distinguished by its governance model. Developed by the City of Achères and SEM SIPEnR within the project company 'Solaire de la Grande Arche', it includes provisions for citizen participation through the support of Énergie Partagée. The City will benefit from economic returns through land rental, tax revenues, and its equity participation.
Citizen participation can be made through Énergie Partagée Investissement, which collects citizen savings. The scheme includes the possibility of investing from around one hundred euros, indirect participation in the project's capital, and representation of citizens in the park's governance for the long term. This investment carries risks and does not guarantee returns or capital recovery.
Beyond electricity production, the project includes an educational dimension with a space dedicated to schoolchildren and residents. Exhibition panels will explain the functioning of solar energy and the challenges of the energy transition, and site visits will also be offered.
The provisional schedule presented by SIPEnR includes the submission of the building permit application in October 2026, the provisional permit acquisition in September 2027, the planned start of construction in October 2028, and the provisional commissioning in the summer of 2029. These deadlines are indicative and depend on administrative and regulatory procedures.
The public meeting, held in a full Wedding Hall, highlighted residents' interest in the development of renewable energy in their territory. The City of Achères thanked the attendees and its partners SIPEnR and Énergie Partagée.
