As part of our quest to help build sustainable cities, we took up the challenge set by the greater Bordeaux area and the Bordeaux Euratlantiquet Etablissement Public d’Aménagement (EPA, public development agency): supplying heating to 570,000 m2 of new-build BBC (low-energy consumption) buildings and linking up 11,000 existing housing units via a heating network that draws 90% of its energy from the Astria household waste recovery plant.

A heating network aimed at reducing greenhouse gas emissions

Greenhouse gas (GHG) emissions contribute to the greenhouse gas effect, which in turn increases global warming around the world. With this in mind, the Bordeaux greater area and its public development agency decided to embark on a mission to reduce these emissions by building an eco-district underpinned by an urban heating network.

We developed a local energy solution in which 90% of the network is powered by the Unité d’Incinération des Ordures Ménagères (household waste incineration unit) in Bègles (UIOM ASTRIA). The Bordeaux greater area’s waste recovery and processing centre lies at the heart of this network.

To ensure uninterrupted service during the UIOM ASTRIA’s maintenance periods, a gas-powered heating system was built at the Bordeaux Brienne Marché d’Intérêt National.

How heating networks work

Heating networks are made up of three major components:

  • A boiler station, a centralised heat production system. There are lots of different types that vary depending on the power and energy sources used: natural gas, biomass, geothermal energy, etc.
  • The pipes, used to transport the heat-transfer fluid (water or steam) and thermal energy.
  • The substations, meaning the exchangers that form the heat delivery points. A substation can be linked to a single building or connected to a series of buildings managed by the same entity.

The advantages of heating networks are:

  • Optimal nuisance management
  • Improved energy efficiency
  • Use of renewable energy.

Unfortunately, they cannot be implemented everywhere.

They require high urban density, space, and availability of renewable local resources.

In this example, the Unité d’Incinération des Ordures Ménagères de Bègles (UIOM) has been transformed into an fully functional heating station.

A cooling system is in place, drawing on recovery of waste heat produced by the unit. The power available to the heating network is greater than domestic hot water need in the summer season. This means that the available waste heat can be absorbed and reused in the cooling system come summer.

Facts and figures

90%  recovered renewable energy

27 000 The equivalent of homes supplied

18 km of network line

15 000 tonnes of CO2 saved every year