District heating networks: The heat is on for social housing providers


19 June 2023

Authored by Stuart Wood, Product Manager – Sustainable Heating, at Polypipe Building Products.

Reducing the carbon emissions produced by heating our homes will be critical to achieving net zero. In fact, according to the Department for Business, Energy and Industrial Strategy (BEIS), the heating sector in the UK accounts for almost onethird of the UK’s annual carbon footprint. What’s more, 17% of the emissions caused by heating buildings come from homes, meaning that heating our homes produces carbon emissions equivalent to the use of all petrol and diesel cars.

To counter this, last year, Part L of the Building Regulations was updated with new guidance which aims to reduce carbon emissions in homes and buildings by 31%. Since then, many in the industry have looked to replace fossil fuelled heating systems with renewables, especially heat pumps. Whilst this is a positive step in the right direction as heat pumps are an ideal solution when it comes to complying with new regulations and reducing carbon emissions, they can be expensive for residents to run. So, in the midst of an energy crisis, specifiers should explore other solutions, such as district heating networks which can not only lead to a reduction in carbon emissions but will also help to decrease energy bills for residents.


The drive for district heating

District heating networks are not a new invention and have been used in the UK since the 1960’s. However, they have not been adopted on a large enough scale. As a country, we are lagging far behind the rest of Europe where heat networks meet about 12% of the EU's heat demand. District heating is commonplace in the Nordic and Baltic regions, and Copenhagen has the world's most extensive district heating system, servicing over an incredible 98% of buildings which is far ahead of any city in the UK.

Despite the lack of district heat network adoption in the UK currently, the government has made it clear that it wants to see a wider uptake of these networks in order to reduce CO2 emissions and meet the targets laid out in the Future Homes Standard. This is because, according to the Government, district heating networks are able to reduce residents’ energy bills by 30%. Currently, only about 2% of the UK's heat is delivered by heat networks, but it is believed that this should increase to 20% by 2050.

As part of its plans to extend district heating capacity, the UK Government launched a £320 million investment programme in In England and Wales in 2018. Since then, there has been a shift in the type of projects applying for funding. Earlier applications tended to be for much smaller schemes, but now much larger schemes are applying, with typical loans of over £1 million being offered. This is a positive indicator that we’re moving towards adopting heat networks more widely, which would have a significant impact on both the carbon and financial cost of heating homes across the UK.


The road to decarbonisation

District heating networks are a system where heat is generated from one central energy source then distributed through an underground network of insulated pipes to provide heat and domestic hot water to several properties. These can be homes in new housing developments, multioccupancy buildings, or a combination of both.

Heat networks can be coupled with renewable technologies such as wind, solar and hydro to provide a cleaner, more sustainable energy system. This means that homes – or multiple homes – can be connected to a reliable and efficient heat source, even if they are not on the gas network, which decreases the reliance on fossil fuels.

One of the main benefits of district heat networks is that they operate at much lower temperatures than traditional gas boilers, meaning they offer a more energyefficient and cost-effective way to heat and cool a property. Specifiers can also reduce the number of required connections by ensuring that these low-energy systems are connected with flexible insulated pipes, which minimises the possibility of heat loss occurring and further improves the system's efficiency.

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District heating networks are also an ideal solution to be paired with lower energy heating systems such as underfloor heating systems. Underfloor heating emits heat via a greater surface area and, therefore, can run at lower temperatures, placing less demand on the central energy source as a result.

These networks also have the potential to harness waste heat from thermal power stations and industrial sites, which would increase energy efficiency even further by utilising energy from nearby sites that would otherwise have been wasted. One existing example of this is that heat from the London Underground is currently being used to provide heat and hot water for homes and businesses in Islington.


A lower cost solution

Whilst there are now a number of lowcarbon solutions available to residents, one of the major drawbacks is that they can be expensive to install and run. When looking for a low-cost option, district heating networks are ideal as the cost of delivering heat to residents could be as little as 24p/kWh per day compared to an equivalent figure of 34p/kWh for electric heating, according to the latest figures from the Department of Business, Energy and Industrial Strategy. Government research has found that district heating networks can cut carbon emissions resulting from new housing developments by up to 70% and create energy bill savings of 30% when compared with electric heaters.

When you consider the current energy crisis and the need to address climate change, these are significant results. If we know that district heating networks can positively impact carbon emissions whilst also providing a more affordable and energy-efficient living environment for residents, as an industry we must embrace them as a solution.


Turning up the heat

Whilst district heating networks are already becoming more common in the UK, increasing industry uptake will go a long way towards ensuring that the government’s ambitious net zero targets are met.

As well as keeping the UK on track towards net zero, district heating networks also benefit residents who will not only benefit from the efficient operation of a system, but also from economies of scale, which will help them to heat their homes at a lower cost in comparison to using individual heating systems.

There is no doubt that we all need to make significant changes if we truly want to decarbonise domestic heating and he government has already committed to publishing the Future Homes Standard by 2025, so the time to act is now and the benefits could be astronomical.