Sustainability and trust as a solid foundation
Technological expertise and long-term partnerships have formed the basis of EnviTec Biogas AG’s activities in the French market for two decades. The company is currently implementing two projects for long-standing customers: the conversion of the “Biowatt” plant in Brittany into a biomethane upgrading facility, and the construction of the new “Valoverte” biomethane plant in south-west France. “Both projects are representative of the trust and satisfaction our customers place in our work,” says Mehdy Benyahia, Managing Director of EnviTec Biogas France SARL responsible for plant construction.
Biowatt: from first project in France to next-generation biomethane site
“The history of Biowatt and EnviTec dates back to 2007. Together with Mr Le Crom, a pig farmer from Rohan, EnviTec established the project company Biowatt for the construction and operation of its first biogas plant in France” says Maurice Markerink, Managing Director of EnviTec Anlagenbau, who was responsible for the development and operation of this project in a previous role at EnviTec. The plant was commissioned as early as 2010. Originally operated using pig slurry, agricultural waste and fats, the facility had an installed electrical capacity of 526 kilowatts. “Over the years, the plant has been continuously expanded and adapted to new regulatory and economic conditions,” Benyahia explains. Through the integration of additional residues from the agricultural and agri-food industries, the installation of a pasteurisation unit, additional digestate storage capacity and an increase in electrical output to 889 kilowatts, Biowatt has developed into a showcase project for a sustainable circular economy.
Despite changes in ownership structure, the partnership with EnviTec has remained intact. “This is demonstrated by the agreement signed in 2025 to convert the plant to biomethane production,” says Benyahia. Conversion works are currently in full swing. The EnviThan gas upgrading unit with a biomethane capacity of 250 Nm³/h is currently being manufactured at EnviTec’s site in Saerbeck, with delivery and commissioning scheduled for the end of 2026.
In addition to installing the EnviThan unit, mixers are being replaced, an existing residue storage tank is being converted into an additional digester, and the digester roof is being renewed. A biogas boiler will also be integrated. “Thanks to the robust original plant design, the conversion focuses primarily on modernisation measures and the integration of biomethane upgrading,” Benyahia adds. A particular challenge lies in carrying out the necessary modifications with minimal downtime in order to maintain the plant’s economic performance during the construction phase.
In future, the biomethane produced will be fed into the network of the French grid operator NaTran. The renewable gas will be transported via a dedicated 13-kilometre shared network to Loudéac, where it will be used for local heat supply in the tertiary sector. The resulting digestate remains in the regional agricultural cycle as a valuable fertiliser.
Valoverte: second project with long-standing partner Cler Verts
Another example of EnviTec’s long-term cooperation with French customers is the Valoverte project, commissioned by the recycling company Cler Verts.
Valoverte is already the second biogas plant realised by EnviTec for Cler Verts and its President Jean-Luc Da Lozzo. The first plant, “Cler ENR” in Bélesta-en-Lauragais, was commissioned in 2015 with an electrical capacity of 637 kilowatts. The new project, featuring an EnviThan plant with a biomethane capacity of 280 Nm³/h, is designed to efficiently utilise organic waste. “In this way, we support our customers in recycling their organic waste, while also avoiding the CO₂ emissions that would result from incineration or landfill and producing high-quality digestate that can replace fossil- and mineral-based fertilisers,” explains the customer. “The circular system we have established for the recovery of organic residues creates optimal conditions for this.”
Earthworks are currently underway. Installation of the tanks is scheduled for September 2026, followed by piping, plant assembly and delivery of the prefabricated EnviThan unit from Saerbeck, with an annual capacity of around 25 GWh of biomethane. Feedstocks include agricultural residues and by-products from the food industry. Depackaging and hygienisation of the substrates will take place at a separate site before being fed into the plant. The wide variety of input materials places particular demands on plant design, requiring robust yet flexible process solutions to ensure safe and efficient operation. From July 2027 onwards, the biomethane produced is expected to be injected into the GRDF network and used for local heat generation.
France remains a strategic growth market
Since entering the French market in 2007, EnviTec Biogas has realised a total of 48 plant projects in the country. The majority of these plants process agricultural feedstocks as well as organic residues and waste. EnviTec Biogas France SARL currently employs 35 people and is headquartered in Plédran, Brittany, complemented by a service site in Le Meux in the Hauts-de-France region. “Local presence is essential, as the French biogas market remains one of the most dynamic in Europe,” concludes Christian Ernst, EnviTec Biogas Area Sales Manager for Southern Europe. With the publication of the multi-year energy plan in February 2026, the government has reaffirmed its ambitions for renewable gases. Targets include biomethane production of up to 62 TWh by 2035. While the development of the biomethane sector has so far been supported primarily by regulated feed-in tariffs, the focus will increasingly shift towards the system of biogas production certificates (Certificats de Production de Biogaz – CPB). The final design of this mechanism is expected in the coming months. The existing remuneration scheme will remain in place but will be gradually limited and increasingly supplemented by the CPB system.
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