Idex, contracting authority of the heating network for a period of 20 years

The Rezé property and land owners’ association (AFUL) gave its support to a project to create a wood heating network supplying energy to the Rezé-Château district. Idex was tasked with this project as part of a 20-year contract.

Idex_chaufferie_reze

 

Our overall mission was to:

  • finance the project,

  • design the facilities required to produce and supply energy,

  • build these facilities,

  • operate and maintain all structures, equipment and facilities, including the heating network and substations serving the homes.

Work to upgrade and extend the heat network is now complete. This involved extending the network from 1 km to almost 7 km.

Operation of the wood heating network

A wood heating network has many advantages:

- it is the only way to make large-scale use of renewable, low-carbon energy. It is a credible alternative to gas or electricity,

- it adapts to fluctuations in the energy market by using non-fossil fuels,

- it also contributes to job creation, with the harvesting, processing and use of fuel wood.

The heating network is made up of a new boiler plant comprising a 5 MW wood-fired boiler and two gas-fired boilers with a total capacity of 13 MW.

The heat produced by the Château de Rezé boiler plant is of the low-temperature type. This means that the pre-lagged, pre-insulated steel heating network distributes water at a temperature of under 110°.
 

Lower energy bills

In 2017, the boiler plant supplied 14,550 MWh to subscribers. Of this total, 69% was from biomass energy in the form of wood chips and end-of-life wood shipped from within a 100 km radius. Idex is committed to supplying heat at a competitive price. Fuelwood is cheaper than fossil fuels, and subscribers also pay reduced-rate VAT.

A few figures

5 MW from fuelwood

12,8 MW from gas

5,5 km for the new network 

1 km of existing network

32 substations, including 22 new ones

5 000 tonnes of fuelwood consumed per year

80% covered by biomass

3,000 tonnes of CO2 emissions avoided in 2017
6,000 tonnes of CO2 emissions avoided since commissioning