What we’re doing
Our plans for a heat network in Exeter
If you’re unfamiliar with heat networks, think of them as big, communal systems that heat multiple buildings rather than just one. Instead of each building having its own boiler or heater, there is one central source that creates heat. This heat is then shared with all the buildings through a network of pipes. It’s a more efficient, and eco-friendly way of heating buildings and it is already used in many countries around the world.
The Exeter Energy Network is a planned Low-to-Zero Carbon (LZC) heat network being developed for the city centre, allowing businesses and organisations to decarbonise their heating systems, along with delivering other benefits to the city of Exeter.
How heat networks work
Established technology
Heat networks are widely used around the world and have helped countries improve energy efficiency while cutting carbon emissions. Denmark, for example, has six large, central heat networks located around major cities and urban areas, in addition to 400 smaller decentralised networks. Today, around 64% of all Danish households are connected to heat networks for heating and hot water and a number of these networks use heat pumps which are powered by renewable electricity. In Copenhagen approximately 80% of buildings are connected to heat networks.
Water Source Heat Pumps (WSHP) work in the same way as a refrigerator, which extracts heat from inside the refrigerator and transfers it out into the environment. A Water Source Heat Pump extracts heat from water before transferring this heat into the network. This process works well even in mid-winter as water temperatures are relatively stable compared to air temperatures.
Like any energy system, there will be occasions when an energy back up is required. Currently, the most cost effective back up option is for the network to use gas boilers. On the coldest days, gas boilers in the Energy Centre would be used to top up the heat provided by the water source heat pumps. Over time, new sources of heat will be added to the network which would reduce the use of the back-up gas boilers.
The gas boilers are expected to initially supply 10-15% of total heat demand for the heat network with 85-90% coming from the WSHPs. To achieve zero carbon, EEN will buy renewable electricity from the grid and other technologies are being considered to move away from gas in future.
We’re also looking at other sources of heat to feed the network and continue the journey to net zero.
Heat networks in the UK
Although heat networks are not as common in the UK as they are in Nordic countries, more and more are being developed.
In the past ten years, the number of homes and businesses served by heat networks has more than doubled to account for around 2% of the UK’s heating supplied to homes and businesses.
UK Government research has indicated that as much as 14-20% of the UK heat demand could be cost-effectively met by heat networks by 2030 and 43% by 2050.
Become a customer
We’re currently focusing on large consumers of heat in the city. We’re also interested in talking to owners of commercial premises and blocks of flats. If you would like to register your interest in a potential connection please contact Exeter@1energy.uk
But for those that are looking now to see if their building is suitable, the primary requirement is to have a “wet” heating system, i.e. heat emitters such as radiators throughout the building connected by pipes to a central plant room, typically housing a gas boiler. If the answer’s yes, the next stage is for us to carry out a survey to understand if any further changes to a building’s heating system are required.
Newer buildings are often simpler to connect because the systems are already set up to run at the kind of temperatures served by the network. However, each building will vary so we would need to carry out a survey to understand what changes would be required in your building to make a connection.
