Heating Whole Districts Through Heat Networks

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Pete Mills, Commercial Technical Operations Manager at Bosch Commercial & Industrial outlines how cities are using heat networks to achieve UK carbon emission targets.

Heat networks, or district heating, are becoming an ever-greater part of our industry’s involvement in larger scale schemes. The ability to help the decarbonization of heat both now and in the future has made them an attractive solution to the new-build sector, as well as those undergoing deep renovation works.

Net zero 2050

The UK’s net zero 2050 target may seem like a long way off. But steps need to be made now in order to reach this, something that our leading cities have recognized.

Many have set their own carbon targets to ensure they stay on track. This is why heat networks’ ability to provide efficient heat and hot water to multiple buildings (and as the name suggests, whole districts) is a particular reason why many cities up and down the country are turning to them as a solution.

What are heat networks?

Generally, heat networks are defined as a system of supply pipes with a centralized heat generator (Energy Centre) that serves multiple domestic or non-domestic dwellings. These are usually in different buildings, but sometimes within a single large building like an apartment block or a university campus.District heating is often used to describe larger scale systems

District heating is often used to describe larger scale systems of this sort, where there will be many buildings connected over a larger geographic area. In these systems, although the heat is provided ‘off-dwelling’, it is also common to have more than one energy centre.

The principle is that energy for heating (and sometimes cooling) is supplied through the system of pipes, with each individual user being metered for the energy they use.

Minimize pipe lengths

Heat networks offer a number of advantages but are best suited to areas where there is high heat density, that is to say where there are multiple ‘households’ close together in order to minimize the length of pipes within the network.

One of the key advantages for heat networks is their adaptability to use any form of heat generation. A key advantage from an environmental perspective is that they make use of waste heat, from sources such as electricity generation, waste incineration and industry.

Heat networks are defined as a system of supply pipes with a centralized heat generator that serves multiple domestic or non-domestic dwellings

The scale of the combined heat requirements of all these dwellings also helps the inclusion of renewable energy sources, which may be more difficult and costly to achieve at the individual dwelling level.

Overall, their flexibility to use whatever heat source is available, makes them easier to decarbonize in the future.
Other key benefits for Local Authorities and Housing Associations have been the elimination of individual gas appliances within dwellings. This has significant cost savings reductions for Local Authorities and Housing Associations where gas landlord checks are eliminated, along with the issues associated with access.

City developments

Today City Councils and developers are opting for heat networks to provide the heating and hot water for new redevelopment projects.

The largest of these is the ambitious Leeds Heat Network, which once completed is set to be one of the UK’s largest new heat networks, connecting 1,983 council homes and numerous businesses in Leeds. The first scheme under the City Region’s District Heating program, the green initiative looks to reduce carbon emissions for the area as well as energy bills for the residents living there.The green initiative looks to reduce carbon emissions for the area

Even more innovative is how the network will connect to the Leeds Recycling and Energy Recovery Facility, which burns black bin bag waste to generate heat. In theory this would make the network fully sustainable.

There will be back-up support from efficient Bosch Commercial & Industrial boilers, which will only be switched on when required, say the colder months where the need for heat is higher.

Climate change targets

An hour’s drive away from Leeds is the city with one of the most ambitious climate targets in the UK. Manchester intends to be carbon-neutral, climate resilient and zero waste by 2038 – 12 years before the overall UK net zero 2050 target needs to be hit.
To help achieve its ambitions, work has been taking place on the Manchester Civic Quarter Heat Network (CQHN).

Manchester hasshown the versatility of heat networks due to the number of commercial buildings it will support

The project will generate low-carbon power, heat and hot water for initially six council buildings and some residential properties with the possibility for the network to grow and connect further buildings across the city centre.

Some see district heating as a solution solely for residential purposes, however Manchester have shown the versatility of heat networks due to the number of commercial buildings it will support.

The project itself has also given Manchester a new landmark, the impressive ‘Tower of Light’, which incorporates the five flues from the technology powering the network. This beacon not only represents the city’s commitment to reducing its carbon footprint but also the innovative nature of district heating.

Heating Battersea Power Station

The final example lies in the Capital and may be one of the most famous developments in the UK at the moment. Battersea Power Station is not only one of the most iconic landmarks in London, but also the center piece of one of the most high-profile, large scale mixed-use redevelopment projects ever undertaken in the Capital.Battersea Power Station is a high-profile, large scale mixed-use redevelopment project

The project involves the development of a district heating and cooling network, with a two-level underground energy centre – one of the largest of its kind. This complex heat, cooling and electricity network will continue to expand as the project continues to undergo its development stages.

Looking ahead

These are just a few examples of cities taking advantage of district heating and its many benefits, but near all cities in the UK have multiple heat network projects underway. Like with most innovations, smaller urban areas should then follow suit.

The importance of district heating will no doubt become more and more prominent. Its ability to power whole areas and multiple buildings can already help efficiency levels, however its potential may be even greater in the future.

One key energy transformation that is looking more and more likely is the decarbonization of the gas grid to hydrogen blends and ultimately 100% hydrogen. If these can be utilized in heat networks then the benefits will definitely put us and UK cities in a good place as we continue our journey towards net zero.

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Pete Mills Commercial Technical Operations Manager, Bosch Thermotechnology

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