Heat networks: a growing source of sustainable and local energy for cities
Heat networks, set up by local authorities in their territories to heat buildings from a collective energy center, make it possible to mobilise large sources of renewable energy that are difficult to access or exploit, particularly in urban areas (wood energy, geothermal energy, recovered heat, etc.). These networks are likely to be developed in the coming years, with a focus on renewable and recovered energy sources in order to contribute to the energy transition. Equans assists local authorities throughout the world in designing, building and operating these district networks.
A district heating system works like a large central heating system that supplies heat to several buildings, a district or a city, through an underground network of pipes. The energy comes from a centralised energy center which produces heat locally from different energy sources: thermal, renewable (biomass, geothermal, solar), heat recovery (incineration of household waste, biogas, wood-waste, etc.). The heat is then distributed in the form of hot water and transmitted to each unit via an individual substation located between the heat network and the building's heating circuit.
There are currently some 6,000 district heating networks in Europe, covering 11 to 12% of needs, with very different situations from one country to another. District heating is by far the most widespread form of heating in Northern and Eastern European countries, whereas it is much less developed in the West, particularly in the Netherlands and the UK.
Heat networks are growing in number and becoming greener
Heat is the leading energy consumption item in Europe, representing more than 50% of energy consumption. The heat network is a sustainable solution for improving energy and environmental efficiency: reduction of CO2 emissions, cost optimisation, lower energy bills, pooling of needs, production of local heat from a renewable energy source, simplicity of operation, reliability of installations, comfort and safety of residents. Heat networks will have to be strongly developed in urban areas over the next few years, combining them as much as possible with renewable and recovered energy. With a 10% increase since 2011, the energy mix of heat networks has already become considerably greener in Europe.
Solid expertise, tailor-made solutions with Equans
From installation to maintenance, Equans has comprehensive expertise and numerous references in heat networks, whether for residential areas, commercial spaces or public facilities, in all the countries where it operates. Each project is carried out with tailor-made solutions adapted to the local context. The energy centers are operated industrially, with a focus on maximum efficiency.
In Belgium and Luxembourg, Equans operates more than 35 heat and/or cool networks
The company is currently starting work on the Usquare site in Brussels: Equans is in charge of the management and overall coordination of the construction of the heat network and the dry and wet networks as part of the transformation of this 3.9-hectare former military site into a mixed-use neighbourhood consisting of a university, housing, public facilities and shops.
In Ottawa, Canada, Equans Services operates one of the country's largest district energy system
which provides heating, hot water and cooling to more than 80 buildings, including the Canadian Parliament. For a period of 35 years, Equans provides operation and preventive and corrective maintenance of the five heating and cooling plants, three of which will be modernized, and the four distribution networks of the system.
In the United Kingdom, Equans operates some of the largest and technically demanding city-wide district energy networks.
In addition, Bouygues Energies & Services Solutions, a subsidiary of Equans, has begun operating the first heat network to supply an entire municipality with renewable energy. Located in Swaffham Prior in Cambridgeshire, this infrastructure, designed and built by Bouygues Energies & Services, is powered 100% by renewable energy sources, namely geothermal and solar. Swaffham Prior will thus become the first British municipality to go entirely without fossil fuels for its heating by 2050.
In the Netherlands, Equans designed, installed and now maintains an innovative geothermal installation that provides 99% of the heating and cooling needs
of the Osterdokseiland district in Amsterdam. Aquifer thermal energy storage (ATES) is an innovative geothermal technology based on the storage of cold and/or hot groundwater in an aquifer.
In Austria, Equans modernizes and operates more than 10 biomass-based district heating networks.
By extending the networks and investing in modern technologies - such as extensive heat recovery from exhaust gases as well as heat pumps - the CO2-neutral heat supply to local municipalities is under way for the next generation.
The word "geothermal" means "heat from the earth". It is a renewable, environmentally friendly energy that is available everywhere and, unlike solar and wind power, does not depend on the weather.
Whether 100 metres below ground or 3 kilometres down, in liquid or vapour form, the heat contained in the earth takes many forms and has many advantages.
Geothermal energy can also be used for passive cooling of buildings. With this solution, the heat from the buildings is captured to recharge the ground via the heat network. This virtuous circle provides free cooling while ensuring that the geothermal system functions properly over the years. Whether for low, medium or high temperature solutions, Equans assists its clients in analysing geothermal potential, meeting technical challenges and ensuring the economic feasibility of projects.
