A citizen wood heating network in Varces (Isère)


In January 2021, the municipality of Varces (8,300 inhabitants), commissioned its wood-fired heating network to supply its public buildings. This system reduces the emission of 295 tons of CO² per year (the equivalent of 1.5 million km driven by car). The project is led by the municipality in conjunction with Energ'Y Citoyennes and ForestEner, with the support of the Auvergne-Rhône-Alpes region, ADEME and Grenoble-Alpes Métropole.

More than one hectare heated with renewable energy

The new boiler room, built in 2020, houses two 250 kW wood-fired boilers that supply eight communal buildings in the town center: the primary and pre-schools, the post office, the recreation center, the cultural center, the auditorium, the gymnasium and the soccer stadium locker rooms. These facilities represent more than one hectare of surface to be heated. The tender incorporated criteria for financing and citizen governance, energy and environmental performance.

During the first five months, the two wood boilers provided 97% of the heating and hot water needs of the eight buildings... Before commissioning, the municipality expected to cover at least 90% of needs.

Thierry Lora Ronco, deputy mayor of Varces

Previously, these buildings were mostly powered by fossil fuel devices. The annual consumption of the network is 1.1 GWh (gigawatt hour). "In the first five months, the two wood-fired boilers provided 97 percent of the heating and hot water needs of the eight buildings. That's much more than we expected," says Thierry Lora Ronco, deputy mayor of Varces, in charge of the ecological transition. Before the commissioning, the municipality expected to cover at least 90% of the needs.

A project with a citizen dimension

In 2019, with the support of the local energy and climate agency of Grenoble, the Varces town council is launching a consultation process for the design of its wood-energy heating network. It is also planning to install a hydraulic distribution system in the gymnasium and the cultural center, which were heated with electricity at the time. The consultation includes criteria for financing and governance of citizens, energy and environmental performance.

The company Forestener was awarded the tender and signed a contract to supply heat for 20 years. Frestener is specialized in the design of wood-fired heating systems and involving citizens in the investment and governance of the projects it runs. To ensure this participatory dimension in Varces, Forestener works in partnership with Energ'y Citoyennes, a company created by residents of the Grenoble metropolitan area with the aim of producing energy from renewable sources.

"We built a communication plan to interest citizens and organized events to mobilize savings throughout the project," explains Fabienne Mahrez, vice-president of Energ'y Citoyennes. This citizen approach has received the "Energie Partagée" label, which guarantees its quality. Energ'y Citoyennes is carrying out two other renewable energy projects with the municipality of Varces: a school roof and a photovoltaic shading system.


Wood energy in a short circuit

The two boilers consume about 300 tons of wood chips per year. These wood chips are supplied by the company ABSRA SAS, whose platform is located 40 km from Varces. In winter, 35 m3 of wood are delivered twice a week.