Séché Environnement wins a major contract in Nantes

Séché Environnement, through its subsidiary Alcea, currently treats part of the waste produced by the city’s inhabitants at the Waste Recovery and Treatment Facility at the Prairie de Mauves, as part of a Public Service Delegation.

Following the consultation, a new public service delegation will take effect on 1^st April 2025, for a period of 20 years, entrusting Séché Environnement with the redesign of the site as well as the operation and maintenance of the current and future Waste Recovery and Treatment Facility.

An innovative, high-performance solution for the energy transition

At the heart of the future Pôle d’Ecologie Urbaine, this exemplary project represents an alliance of territories at the service of the environmental and energy challenges of the future.

The new Waste Recovery and Treatment Facility, designed by Séché Environnement and Paprec Engineering, will feature innovative and 100% French technologies. It will be a high-performance energy and environmental facility, meeting waste recovery needs while producing the energy required by neighboring areas.

The Groupement d’Autorités Concédantes (GAC) emphasized the ability of Séché Environnement and its partners to offer an innovative, high-performance solution that meets environmental requirements:

• Atmospheric discharge thresholds well below regulations, and on certain parameters, below the requirements of Nantes Métropole,
• Control of the Waste Recovery and Treatment Facility’s environmental impact: optimized management of rainwater consumption, zero discharge policy at the wastewater treatment plant, special attention to noise and odor impact (particularly during the works phase), implementation of an ambitious policy to preserve biodiversity, and strict application of Nantes Métropole’s Sustainable Worksite Charter,
• Optimized energy recovery: Séché Environnement is committed to supplying more power to the urban heating network than is required by the specifications, to meet the needs of Nantes Métropole and prepare for the future. In addition, Nantes Métropole has been offered the opportunity to acquire a 5 MW strip of electricity at a fixed price, thus ensuring advantageous long-term economic management.

Optimized energy performance to produce the energy of tomorrow

The new facility will offer an innovative industrial ecology solution, with a waste treatment capacity of 270,000 tons authorized by prefectural decree. This project interests 1.5 million inhabitants.

It will generate electricity for more than 25,000 households, cover more than 75% of the heating needs of the Centre Loire urban network (with a guaranteed output of 48 MW) and produce cooling during the summer (with a guaranteed output of 10 MW).

With its ambitious energy output, this project will double the performance of the previous waste-to-energy plant.

An exemplary, forward-looking facility serving the ecological transition

Located at the heart of the Pôle d’Ecologie Urbaine, the new facility proposed by Séché Environnement will provide a solution perfectly suited to local needs.

The facility will combine industrial efficiency with optimized performance. A model of transparency and education, the site will include an immersive exhibition enabling visitors to discover how it works and to understand its essential role in waste treatment.

Recognized expertise in the management of complex waste recovery units

Séché Environnement, with its strong local presence, brings together partners and local stakeholders committed to the success of the project, including:

• Paprec Engineering (formerly CNIM, which designed and built the plant in 1983), responsible for the design and construction of the Energy Recovery Unit,
• Legendre, a major local family-owned construction group, in charge of civil engineering,
• AIA Life Designer, a multidisciplinary architectural firm based in Nantes, in charge of architectural design (in collaboration with AT2E), project management and urban, environmental and landscape integration,
• AT&E architects, specialists in architectural integration, responsible for architectural design (in collaboration with AIA), project management and functional layout,
• As well as two specialist design firms: Sepoc (assistant to the project owner) and Naldeo (assistant to the project owner).

‘We are very proud of the renewed confidence shown by Nantes Métropole and its partners in this major contract. It is a testament to our long-standing commitment to energy transition and waste recovery in the Pays de la Loire region. This partnership reflects our ambition to contribute to a sustainable future with innovative, high-performance solutions for local authorities. We are determined to continue our work alongside Nantes Métropole and its partners to create an ever more virtuous model of territorial ecology, benefiting all partner local authorities’, declared Maxime Séché, CEO of Séché Environnement.