Rennes adopts roadmap to expand district heating substantially by 2035 

On May 15, 2025, Rennes Métropole approved a new roadmap to guide the development of its heating networks through 2035. This plan aligns with the region’s Climate-Air-Energy objectives, aiming to expand and modernize urban heating infrastructure to reduce greenhouse gas emissions and address energy poverty. By 2035, district heating is expected to supply the equivalent of 84,000 housing units, representing about one-third of all households in the metropolitan area. 

The plan includes significant extensions to the two primary existing networks: En’RnoV in the northeast and Enersud in the south of Rennes. The southern network will see 32 kilometers of new pipelines added to the current 47 kilometers, with plans to extend into the neighboring municipality of Saint-Jacques-de-la-Lande. Authorities also anticipate interconnecting these two historical networks around 2030. By 2035, the southern Enersud network is projected to operate fully on renewable energy, while En’RnoV is expected to reach a renewable energy share of 75%. The primary energy sources will be heat recovery, wastewater treatment, and biomass, supplemented by some fossil fuel usage. Future integration of other renewable technologies such as geothermal and solar thermal energy remains a possibility, contingent on forthcoming support from the French ecological transition agency (Ademe). 

Beyond these established networks, Rennes Métropole is advancing several smaller heating projects. In Vezin-le-Coquet, a network in operation since 2010, the objective is to increase coverage from 500 to 900 equivalent homes by 2035, with 85% of energy derived from renewable sources. In Le Rheu, pipeline construction began in late 2024, and a biomass boiler facility is scheduled for summer 2025, aiming to serve 600 homes with 83% renewable energy by mid-2026. Chartres-de-Bretagne’s network, which served about 100 homes with 53% renewable energy in 2019, is also expanding within the Portes de la Seiche development area, with plans to reach 600 homes. 

Additional areas, such as zones in Cesson-Sévigné’s Via Silva development and Bruz’s Ker Lann sector, are currently under evaluation for potential heating network expansion, particularly in relation to new residential developments, including student housing. 

The roadmap further considers the evolving role of heating networks in providing urban cooling solutions to combat heat island effects. While pilot initiatives exist in cities like Marseille and Montpellier, the implementation of cooling through heat networks remains costly, and Rennes continues to explore feasible approaches for future deployment. 

Read more in article from Rennes Metropole  

Avignon selects Dalkia to develop major district heating and cooling network

In April 2025, the Avignon city council voted to create a large-scale district heating and cooling network that will supply clean, affordable energy to 17,000 households as well as public and private buildings. Construction is set to begin next year, and Dalkia, a subsidiary of EDF, has been selected under a 29-year public service delegation to develop and operate the system through 2054. 

With an investment of 121 million EUR, the network will eventually stretch across much of the city, delivering both heating and cooling through underground pipelines. This makes the networks one of the examples of cooling networks in France, with known precedents in for example Marseille. 

The initiative, conceived in 2022 and modeled in part on similar systems in Le Havre, combines geothermal energy, heat recovered from the city’s wastewater treatment plant, photovoltaic solar panels, biomass, and green gas. This hybrid mix is expected to avoid 737,000 tonnes of carbon emissions over its lifetime, roughly equivalent to the emissions from 6 billion kilometers driven by car. 

Targeting primarily working-class neighborhoods around Avignon’s ring road that are significantly exposed to energy poverty, the project will also serve schools, hospitals, sports centers, and administrative buildings. New developments such as Joly Jean and Bel Air, as well as areas like Agroparc, Montfavet, and the Piot and Barthelasse islands, are included in the proposed expansion. The historic city center, however, is excluded from the current perimeter. 

The city has also previously laid the groundwork for connections to the network by acquiring legacy heating infrastructure in social housing complexes such as Triennal, Grange d’Orel, Monclar, and Grands Cyprès. These networks, originally gas-based and dating from the 1970s, will be integrated into the new centralized system. According to Mes Infos, tenants of major social housing providers Grand Delta Habitat and Érilia will be among the first to benefit. 

This project complements Avignon’s broader energy transition strategy, launched in 2014, which has already led to a 15% drop in municipal energy consumption. Users are furthermore expected to see lower and more stable energy bills, with projected rates falling from 128 EUR to around 107.80 EUR per kilowatt-hour. The long-term stability of the tariff is one of the key economic motivations for the project. 

Read more in article from Mes Infos  

Roanne begins construction of biomass heating plan to expand district heating in the area

The city of Roanne and Dalkia has initiated the construction of a new biomass-fueled heating plant that will significantly expand its district heating capacity. The project aims to supply renewable heat to the equivalent of 7,000 homes, including key public buildings such as the city hospital, town hall, schools, and a new senior residence. Completion is expected by the end of 2026. 

The new facility, with a capacity of 8.8 megawatts, will be located at 34 boulevard Jean-Baptiste Clément, adjacent to an existing biomass installation. Furthermore, with the newly installed capacity, the district heating network will be extended from 3 to 14 kilometers, significantly increasing its reach across the city. 

The total cost of the project is estimated at over 30 million EUR. This includes 12.5 million EUR for the construction of the heating plant and 15.5 million EUR for the extension of the network. Financial support includes 11 million EUR from the French Agency for Ecological Transition (Ademe), along with funding from energy savings certificates.  

The project emphasizes environmental sustainability, both in energy production and construction practices. Approximately 2,000 tonnes of deconstruction materials will be reused on site, reducing reliance on new resources and limiting construction-related vehicle traffic in the city. The new heating system is furthermore expected to reduce annual carbon emissions by around 10,000 tonnes. Furthermore, local officials anticipate that the project will contribute to more stable and potentially lower heating costs for residents.  

Read more in article from Mes Infos 

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