See our 'About us' page for information on the project, and to learn more about the team.

A district heat network refers to a heating system which uses a common heat source (or sources) for use by multiple users. Like a traditional boiler supplies heat for your home, a heat network uses a central plant to capture the heat, and then a network of pipes around the community to distribute the heat to buildings. You can think of the heat network as central heating system for the whole community. The energy plant acts as a ‘boiler’, and the distribution network of pipes delivers heat to each connected building in the community, like if each building were a room in a house. You are in control of your individual home’s heating, just like you can control individual radiators in a house. There are many potential sources of heat for use in a low-carbon district heat network, but they can be broadly categorised into the two types below. Historically, heat networks have regularly been developed to use gas as a heat source, however these types of networks are being phased out for zero-carbon alternatives. - Renewable sources of heat. This refers to heat that can be sourced from ‘untapped’ renewable sources in the natural world. For example, capturing latent heat from a waterway, such as a river or lake. - Waste sources of heat. This refers to heat that can be captured from existing industrial processes that would otherwise be wasted. An example of this would be capturing and using heat caused as a by-product of incinerating rubbish. As there are no large sources of ‘waste heat’ near to Kings Langley, this feasibility study is focusing on using the first type of heat: heat that can be captured from ambient, renewable sources. There are still a number of ways a network like this could work, but generally, a ‘heat exchanger’ captures heat from near the source and transfers this heat into the insulated pipes around the network. In the example of capturing heat from a waterway, water would be extracted to the nearby energy plant where the heat would be transferred to the network. The water would then be returned to the waterway, at a slightly cooler temperature. The water only interacts with the network at the heat exchanger, so there is no risk of water becoming polluted, or vice versa. Once the heat is within the network, it is distributed from the energy plant to individual buildings via the network of insulated pipes. This can include domestic, commercial, and public buildings.

Zero carbon District heating is playing a vital role in the clean energy transition, and the move away from heating our homes with gas. Currently in the UK, heat networks reduce carbon emissions in buildings by around 1 million tons of CO2 each year, as opposed to if the buildings were heated in traditional ways. This equates to 3,065GWh of gas per year not being burned, enough to heat 216,000 homes. It is estimated that by 2030, as more heat networks are established, that 5.7 million tonnes of CO2 will be saved per year in the UK. Affordable District heating networks are competitive in terms of pricing with individual heating. They are not fundamentally cheaper to run than a gas boiler, but importantly, the renewable heat sources used within a district heat network allow for long-term price stability. Customers of a heat network are not at the liberty of a volatile gas market, so are not at risk of price hikes in their heating bills. A range of funding options are available to install the heat network, in order to minimise up-front costs to those wishing to connect to the network Community-led Developing a district heat network provide can empower a community to make decisions on how their homes are heated, and how the network will operate. A range of governance and ownership options exist for district heat networks. The choice will depend on what is most suitable within the context of a specific community. Options can include co-operatives or local government ownership of the heat network.

We are currently within the first phase of the heat network development process. This involves a desk-based feasibility study of a heat network within the parish and having an open dialogue with the community. If a heat network is found to be a viable option within the parish, any further work will be developed collaboratively with the community in a transparent way. We are working for you, so the scheme will only progress if you are on side. If a heat network were to be developed in the parish, some disruption would occur over a few weeks during the installation of the distribution pipe network. The specific types of disruption, and length of works, would depend on the type of network that would be installed, and would also likely include upgrades to the insulation of homes that would be connected to the network, where necessary. That being said, our experienced teams would ensure that any disruption would be minimised with careful planning and a continued open dialogue. It’s worth remembering that a few weeks of disruption would support decarbonised heating in the Parish for generations!

Carefully planned district heat networks should not cause damage to the local environment. The Environment Agency, and local authority ecology and environmental health departments must be consulted during the planning process to ensure that the development and operation of a heat network would not negatively impact wildlife. Any plans must satisfy the requirements of these regulatory bodies, otherwise permission will be refused. For example, in the case of a district heat network collecting heat from a waterway, such as a river, the abstraction point (where water is taken from the waterway) is designed as to not trap or harm any wildlife. The water itself passes through an advanced filtration system, and only interacts with the heat network at the ‘heat exchanger’ as to not be polluted (and to protect the network from pollutants). To further avoid any negative impacts on the waterway, there is a strict range of temperature that the water returning to the waterway must stay within. The temperatures and quality of water returned to the waterway must be monitored and the data submitted to the Environment Agency as a condition of license. If the water is being returned in a condition which breach the license, the Environment Agency can impose a fine or revoke the operating license.

As mentioned in the 'Benefits of heat networks' section of the FAQ, district heat networks are competitive in terms of cost with individual heating of homes and can provide long term price stability for energy. A 2017 survey from the Department for Business, Energy and Industrial Strategy (BEIS) showed that that the majority of heat network users were happy with costs and performance. However, the initial installation of a heat network- including all necessary infrastructure and insulated pipe network- does require a significant capital investment up front. To minimise this upfront cost, a range of funding options are available to install the heat network. For example, low interest finance and payback options which would involve users of the system paying a 'service charge' to pay for the cost of the system over a long period of time.

Heat networks currently provide around 2% of the UK’s heating needs. Approximately 17,000 heat networks in the UK supply around 500,000 customers. Below, you can find information on a selection of existing district heat networks within the UK...

Swaffham Prior is a village of around 300 homes in East Cambridgeshire, it will become one of the first villages in the UK to install a heating network into an existing community. Homes in the village aren’t connected to the gas grid and currently 70% of homes rely on burning oil for heating. This is an unsustainable, high in carbon emissions and expensive fuel source. The Swaffham Prior Community Land Trust spearheaded the pursuit of exploring how renewable energy could be brought into the village. The ambition has been to: End fuel poverty Reduce dependence on oil Provide cheaper, renewable heating to as many homes as possible In 2018, the community trust commissioned a study into alternative heating options, this was delivered by ourselves, Bioregional, it identified the potential for a village-wide heat network. A range of heat sources were considered – including biomass from local straw – but the key to unlocking the project was a parcel of land on the edge of the village owned by Cambridgeshire County Council (CCC). This opened up the possibility of generating heat using a GSHP system. Following a series of further technical studies funded by the Department for Business, Energy and Industrial Strategy’s Heat Network Delivery Unit , it was decided to use Ground Source and Air Source Heat Pumps to provide thermal energy, pumped through a community network, into homes in Swaffham Prior. The Air Source Heat Pumps will act as lead from mid-April to early October. They will be used all year round, but make a comparatively smaller contribution in winter with a switchover to Ground source heat pumps in the winter. Back up heating is to be provided by 1.5MW electrode boilers (effectively, large immersion heaters). Four large thermal stores have also been specified to meet short-term peaks in demand and provide resilience. In addition, the scheme will be linked to a private electricity network connected to a 28MW solar farm owned by Cambridge County Council. The electricity generated by the solar farm that will be consumed by the Swaffham Prior network and energy centre would have otherwise been sold to the wider national grid. It is predicted that the vast majority of electricity consumed by the network will be sourced from the solar farm. To date over half the village have already outlined their intention to join the Community Heat Network, with residents signing up to a Heat Supply Agreement, consumer protection is expected to be covered by OFGEM. This is to ensure that residents don’t pay a premium for their community supplied heat. The price of heat is linked to the price of heating oil. The project capital costs are £11.9m, which are being funded by a £2.9m grant from the Heat Network Investment Project and capital borrowing by the council. The cost over the life of the project will be covered by heat charges and income from the Renewable Heat Incentive. Currently, the installation of the heating mains and the construction of a local renewable energy centre is under way. It is hoped that in spring 2022, the first homes will connect to the heat network. It is predicted that there will be a gradual ramping of connections over the first five years, with a target of around 100 properties in the first 12 months. The images below show the installation of the heat network pipes throughout Swaffham (left), and a rendering of the energy centre for the heat network (right).

In 2012, 18 flats were retrofitted to use a district heat network, as residents had previously complained about the high cost/poor control of the existing electric storage heaters. The heat network involved installing 3 ground source heat pump (involving 28 boreholes) to serve the 18 flats, with heat being delivered through radiators. The scheme also involved the homes being retrofitted to improve their insulation. Following installation, the residents have been very satisfied with the new system. The images below show the lawn of a home after connection to the heat network (left), and the construction process of connecting homes to the network (right).

Kingston Heights is a mixed-use development, in operation since 2013, comprising of 137 apartments (56 affordable), and a 145 room Hotel within Kingston-upon-Thames. The development is heated by a district heat network, using water source heat pumps to collect ambient heat from the River Thames. Heat exchangers transfer low grade heat from river to internal ‘closed’ loop water system. The heated water can then be distributed to the apartments, which each contain a heat pump connected to a hot water cylinder, and an underfloor heating system. The heat network saves over 500 tons of CO2 emissions per year as opposed to using a gas combined heat and power (CHP) plant. The images below show the completed development (left), and installation of the heat network piping (right).

Conceived in 2010, this development comprises of 550 residential units (6 blocks) and 2,973m2 of commercial space. A district heat network heats the development, which uses open loop ground source heat pumps and gas combined heat and power (CHP) to provide lower carbon heat, hot water, and electricity. The heat pumps draw water from four wells 100m deep under the site. These combine with gas boilers and CHP in the on-site energy centre. The heat is then distributed to homes via underfloor heating. Lower cost of operation, lower carbon, and lower tariffs for residents. It is estimated that these heat pumps compared to traditional gas boilers save 132 tonnes of CO2 per year.