Heat networks and climate change

Emissions from heating UK

 

 

 

 

 

 

 

 

Approximately 40% of the UK’s energy consumption and 20% of our greenhouse gas emissions are due to the heating and hot water supply for our buildings[1]. Infographic from the CCC (see below).

Legislation

The UK government has legislated that we must reach net zero greenhouse gas emissions by 2050. This provides the legal imperative to decarbonise the heat sector, but also means that the UK will need to eliminate almost all emissions currently produced by heating and hot water consumption[4].

Efficiency

Heat networks supply heating more efficiently than individual heat generators per property, through economies of scale i.e. having one large heat generator and piping the heat to each property. They are therefore most efficient in heat dense areas, where space is limited and pipework would be shorter between properties.

Fuel source

Heat networks are also fuel agnostic, and so can be heated by low carbon heat generation from construction, or switch to an alternative source of heating later. See here for some examples of renewable sources of heat for heat networks in the UK already, from waste to geothermal. Additionally, thermal stores are increasingly used to balance demand swings, which are typically large insulated tanks of water that can store excess heat from generation at low periods of demand.

Historywhy heat nets block

Heat networks have been widely used in Denmark since the 1970s, and are an established technology. However heat networks only supply 2% of the UK’s heat demand currently, having developed the gas grid as its main heating source since the 1970s. We are preparing a timeline for how the history of heating in the UK has developed, which will be published soon. Even so, approximately 13% of households in the UK are currently not connected[2] to the gas grid, where heating is supplied largely by oil heaters and sometimes electricity, or heat networks.

Government support

As part of their commitments to reducing their carbon emissions, the UK and Scottish governments are supporting the development of heat networks, through investment incentives and developing regulation which will support the sector.

According to the CCC, heat networks could extend to cover 18% of the UK’s heat demand by 2050.

[1] https://www.theccc.org.uk/publication/next-steps-for-uk-heat-policy/

[2] https://www.gov.uk/government/statistics/sub-national-estimates-of-households-not-connected-to-the-gas-network

Committee on Climate Change’s advice

The Committee on Climate Change (CCC)[1] is the independent advisory body to the UK government on targets and progress made in reducing greenhouse gas emissions and preparing for climate change. The Committee identified what it calls low-regret routes to reducing emissions from heating buildings that the Government should pursue immediately which included “the roll-out of low-carbon heat networks in population-dense urban areas, along with energy efficiency and other measures”.

In its latest advice to the UK Government on the UK’s ‘carbon budgets’, the Committee[2] recommended growth in heat networks, with up to 18% of heat demand met by heat networks by 2050 (see table below) from a current baseline of about 2%.

     Year     Fraction of UK heat demand served by heat networks
2020
2030
2050
3%
10%
18%
 

Their recommendations also included a major programme to build and extend low-carbon heat networks in heat-dense areas, connecting 1.5 million homes by 2030[1] and reaching 5 million homes by 2050[2].

This encompasses both retrofitting existing homes (there are about 29 million homes currently in the UK) as well as new homes. This comes in conjunction with advice that after 2025, no new homes should be connected to the gas grid, and that new homes should have low-carbon heating systems instead[3].

The CCC also emphasised the expansion of non-domestic connections to heat networks, which in their ‘central’ scenario would account for 53% of total heat delivered by heat networks by 2050 (although only 28% of UK heat demand is non-domestic). Non-domestic buildings are largely concentrated in urban areas with a higher heat density, where heat networks are more likely to be deployed.

The UK government department for Business, Energy and Industrial Strategy (BEIS) set out the context of the government’s support for heat networks and the role of the sector in the decarbonisation of heat in a report in December 2018. This responded to the CMA’s market study[5] and the ADE’s Shared Warmth report[6] on the heat network market.

Government acknowledged that in the Clean Growth Strategy, they have set out a significant role for heat networks as a ‘low regregts’ component of meeting their decarbonisation commitments. They recognised that for the last 50 years we have largely relied on gas to heat our buildings, and heat networks are a key technology which can facilitate the transition away from fossil fuels towards low carbon energy sources.

See https://www.gov.uk/guidance/heat-networks-overview or our existing legislation section for more information on how the UK and Scottish governments are supporting heat networks. Also see our reports section for further reading on the development of the heat network market in the UK.

  

[1] https://www.theccc.org.uk/

[2] https://www.theccc.org.uk/publication/the-fifth-carbon-budget-the-next-step-towards-a-low-carbon-economy/

[1] https://www.theccc.org.uk/publication/uk-housing-fit-for-the-future/

[2] https://www.theccc.org.uk/publication/net-zero-the-uks-contribution-to-stopping-global-warming/

[3] https://www.theccc.org.uk/publication/uk-housing-fit-for-the-future/

[4] https://www.theccc.org.uk/wp-content/uploads/2019/05/Net-Zero-Technical-report-CCC.pdf

[5] https://www.gov.uk/cma-cases/heat-networks-market-study

[6] https://www.theade.co.uk/resources/publications/shared-warmth-a-heat-network-market-that-benefits-customers-investors-and-t