Rural and Environment

What are ‘heat networks’?

September 3, 2019 by johnfitzgerald No Comments | Category Uncategorized

Every day more than 800 heat networks are supplying warmth and hot water to over 23,000 households in Scotland.

This innovative and environmentally friendly way of supplying heat involves a distribution system of insulated pipes that carry hot water or steam from a central source and deliver it to homes and businesses.

Networks can vary in size and length, carrying heat just a few hundred metres between houses and flats or several kilometres to supply entire communities and industrial areas. The distance a network can reach is  easily extended by simply adding more providers of heat, or ‘heat sources’, along the way.

Examples of that can be found in large European cities such as Copenhagen where approximately 98%[1] of all buildings are connected to a heat network. In Warsaw heat network covers approximately 56%[2] of the city.

Heat can come from a wide range of sources such as recovered heat from industrial processes, renewable technologies, from combined heat and power using traditional fossil fuels, energy from waste and from thermal storage heated by renewable technologies such as wind.

Heat is brought into each building through a ‘heat exchanger’ which, for a residential connection, is about the same size as a small gas boiler. The heat exchanger works by capturing the heat from the external network of pipes and transferring inside the home to provide hot water for baths, showers and radiators.

All the same heating controls that appear on a conventional boiler are available and the central heating and hot water system works in exactly the same way as a domestic gas-fired central heating system, but without the need for any combustion to take place inside the building.

Why do ‘heat networks’ matter?

Heat networks provide a unique opportunity to exploit larger scale and often lower-cost renewable and recovered heat sources that otherwise cannot be used. For example, a network recently opened by First Minister Nicola Sturgeon in Stirling harnesses heat from a waste water treatment works operated by Scottish Water.

The facility pumps low-cost, low-carbon heat to a number of key public buildings, including a leisure centre, a sports stadium and a secondary school. You can learn more about Stirling District Heat Network project by clicking here.

Once network infrastructure is in place, the heat source can be adapted in time to the most affordable, efficient and green solution available. They can also help to balance the energy system, which makes them one of the solutions for countries like Scotland, where we have an abundance of wind energy which otherwise may not be harnessed.

Appropriately-sited, low carbon heat networks are therefore one of the heat decarbonisation technologies that will support Scotland to meet emissions reduction targets.

This is in line with advice from the Committee on Climate Change that decarbonisation technologies that are relatively low cost and which provide large benefits should be deployed while options for wider heat infrastructure – such as decarbonisation of the gas grid – are examined.

Future development of heat networks

Policy related to the gas grid is reserved to the UK Government, but the Scottish Government is already making use of its devolved powers by preparing legislation to support the development of more heat networks in Scotland through introducing regulation.

The proposed regulatory package was developed though a number of consultations and working groups with the public and experts to ensure it maximises benefits for Scottish people and businesses.

Further detail on the content of the Bill will be published in a Ministerial Statement in the coming weeks, but its overall purpose will be to help grow the market by providing greater certainty to investors and increasing consumer awareness and acceptance of heat networks.

This will help to make Scotland a more attractive place to develop heat networks, supporting our shared efforts to reduce our greenhouse gas emissions.

[1] https://www.c40.org/case_studies/98-of-copenhagen-city-heating-supplied-by-waste-heat

[2] https://www.euroheat.org/news/warsaw-district-heating-upgrades-cut-air-pollution/

Tags: energy, heat networks, programme for government

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