Developed by GreenYellow, international leader in decentralized energy transition and partner of Eaux de Normandie, a SUEZ subsidiary and operator of the wastewater treatment plant on behalf of the Caux-Austreberthe Community of Municipalities, the
photovoltaic plant covers an area of 1,200 m². Its
603 solar modules will
generate 269 MWh of green electricity each year,
supplying 25% of the site’s energy needs. This local production will also
reduce annual CO₂ emissions by 18 tonnes, marking significant progress toward
self-consumption and a lower carbon footprint for the facility.
The solar installation is financed by
GreenYellow, which delivers the entire project - from feasibility studies and financing to design, construction, operation, and maintenance - over the full contractual term, under a
20-year PPA, in partnership with the plant operator
Eaux de Normandie. All the green electricity produced by the photovoltaic plant will be self-consumed by the facility, covering 25% of its electricity requirements. Construction began in September 2025 and was completed in December 2025.
This project fully aligns with the
commitments of the Caux-Austreberthe Community of Municipalities to responsible and innovative water and wastewater management. This momentum was recognized in 2025 with the award of the
“Water Territory in Ecological Transition” label granted by AMORCE. To date, several major projects have been completed or are underway across the territory, representing in concrete terms:
- Estimated annual production: approximately 10,050 MWh, equivalent to the consumption of 2,500 households, or around 5,000 residents.
- CO₂ emissions avoided: approximately 553 tonnes per year, equivalent to removing 350 to 400 internal combustion vehicles from the road, avoiding more than 2 million vehicle kilometers each year, or the annual heating consumption of nearly 250 homes.
Caux-Austreberthe’s progress toward the Climate, Air and Energy Plan objectives over two years: approximately 23.5% already achieved.
Beyond this installation, since 2023 the wastewater treatment plant has been part of a broader renewable energy approach. All of its energy consumption, as well as that of all wastewater infrastructure across the territory, is supplied with 100% green energy, representing an annual production of 1,000 MWh - the equivalent of the consumption of 107 households.
Since 2023, several optimization initiatives have also been implemented to improve site performance and
reduce energy consumption:
- Intelligent control of biological basin blowers using artificial intelligence, delivering 7% energy savings.
- Optimization of the sludge treatment line, including pump replacement and improved loading conditions.
- Enhanced performance monitoring through precise indicators for finer, more responsive management.
- Smart monitoring of the wastewater network through sensor deployment to track clogging in real time, optimize interventions, and reduce travel.
- Deployment of Sewerball, an innovative SUEZ Group technology used to inspect pipelines, improve network knowledge, and prioritize preventive maintenance.
Thanks to all these measures, the plant reduced its overall energy consumption by 15% between 2022 and 2024.
The inauguration of this photovoltaic solar power plant once again highlights the strong commitment of the Caux-Austreberthe Community of Municipalities and its partners to accelerating the ecological transition, strengthening the territory’s energy autonomy, and sustainably controlling wastewater management costs.
Key figures
- 175 km of wastewater network
- 10,500 subscribers
- 2.3 million m³ treated at the Villers-Écalles wastewater treatment plant
ABOUT GREENYELLOW
GreenYellow, a French company founded in 2007, has become in 18 years a major player in the energy transition in France and internationally, and a true partner of corporates and local authorities in their decarbonization journey and quest for energy independence.
As an expert in decentralized solar photovoltaic production, energy efficiency programs, energy storage, and electric vehicle charging infrastructure, GreenYellow supports its clients across the entire value chain. The group ensures the study, financing, development, and operation of assets that allow them to produce green, local, and competitive energy, reduce their energy consumption, while strengthening their competitiveness.
In 2024, the projects carried out by GreenYellow helped avoid the emission of almost 546,000 tons of CO₂ equivalent. The group also aims to achieve carbon neutrality (“Net Zero”) for scopes 1 and 2 by 2040.
Operating in some 15 countries across 4 continents, GreenYellow innovates by constantly enriching its unique and global platform of offers to support its 1,400 clients in their transition to a more sustainable energy model and meet the challenges of climate change. 🔗 www.greenyellow.com/en
ABOUT THE COMMUNITY OF MUNICIPALITIES CAUX-AUSTREBERTHE
The Caux-Austreberthe Community of Municipalities is a rural and peri-urban area of Seine-Maritime, which has long been committed to sustainable and innovative management of local public services. It is responsible for collective sanitation throughout its perimeter, ensuring the collection, transport and treatment of wastewater for more than 10,000 subscribers, through a network of approximately 175 km and a main wastewater treatment plant located in Villers-Écalles.
Concerned with combining service performance and cost control and ecological transition, Caux-Austreberthe has embarked on an ambitious strategy of energy sobriety and innovation, including the use of renewable energies, the optimisation of installations and the deployment of intelligent management tools, an approach recognised by obtaining the "Water Territory in Ecological Transition" label.
ABOUT EAUX DE NORMANDIE
Located in the 5 Normandy departments (Manche, Calvados, Orne, Seine-Maritime and Eure) where it employs more than 200 people, Eaux de Normandie provides homes, communities and businesses with a vital resource: water. It operates on more than 60 drinking water production sites and more than 3,500 km of networks that serve more than 170 municipalities.
The company also collects wastewater from more than 150 municipalities with the maintenance of more than 1,600 km of networks and the management of more than 90 wastewater treatment plants.
In addition, it contributes to the preservation of the resource and the natural environment, as well as to reflections on issues of access to water and governance.
ABOUT SUEZ
For more than 160 years, SUEZ has been providing essential services to protect and improve quality of life in the face of growing environmental challenges. SUEZ enables its customers to provide access to water and waste services through innovative and resilient solutions. Present in 40 countries with 40,000 employees, the Group also enables its customers to create value throughout the life cycle of their infrastructures and services, and to lead their ecological transition by involving their users.
In 2024, SUEZ provided drinking water to 68 million people worldwide and sanitation services to 44 million people. The Group produced 8 TWh of energy from waste and wastewater. In 2024, SUEZ generated sales of €9.2 billion.For more information: www.suez.com / Twitter @suez
