District Energy: a proven, low-carbon, flexible heating solution

By Dom Barton, Metropolitan Infrastructure

 Opting for district energy is a long-term commitment. Networks are assets that need to be managed for years; a well-designed network can be expected to be in operation for up to 80 years. It is therefore essential that energy managers make an informed choice about district energy. They need to be aware of how flexible a heating solution it is, able to change and adapt as heat and power generation technology and low carbon targets change, yet still deliver the heat and cooling required, efficiently and at an affordable price for the consumer.

Delivering good quality service

District energy networks serve entire communities, delivering all the heat that each community needs. Since the residents and customers have no alternative heat options, it is essential that the network delivers heat where and when it is needed, provides excellent customer service and represents good value over the long-term. The evidence suggests that this is indeed the case in practice with district energy.

Last year the Department for Business, Energy and Industrial Strategy (BEIS) undertook the first-ever survey of heat network customers. The survey was carried out by independent researchers between April and July 2017 and received over 5,000 responses from users of both communal and district energy networks. The results, published in December, were very positive for the district energy network sector. They suggested that heat network consumers paid, on average, around £100 less for their heating and hot water compared with non-heat network consumers, whilst being overall just as satisfied with their heating.

One of the key drivers of satisfaction was the level of information provided about the system.  Networks that were members of the Heat Trust achieved particularly impressive consumer satisfaction levels concerning the quality of billing and usage information they received. The Heat Trust is an industry-led, self-regulatory initiative supported by the UK Government, which recognises best practice. The service standards and customer protection requirements include: billing and payment arrangements; fault and emergency reporting; complaint handling; and privacy policy and data protection. Metropolitan’s scheme at King’s Cross was amongst the first to be registered.

Delivering low-carbon development

District energy therefore is clearly delivering for the consumer, but it is also delivering for the wider community by contributing to low-carbon development. Heating accounts for more than 40% of UK carbon emissions. So, the savings that district energy networks offer are vital in helping to meet new stringent carbon-emission targets. Compared to traditional utility solutions, district energy can deliver more than a 50% saving in carbon emissions. Furthermore, any spare power generated is not wasted and can be used to run a cooling network; a solution known as tri-generation.

Flexibility built in

It is flexibility like this which is such a valuable characteristic of district energy networks. Once a network has been installed, it can be expanded as required. More heat sources can be added to the energy centre and older buildings can be retrofitted as their heating systems need renewing. These systems also work well with large, phased developments delivered over a number of years. At each stage, the energy centre capacity can be matched to the size of the development as it grows, avoiding unnecessary over-servicing but meeting planned, community needs.

Finally, there is the enormous potential of new sources of heat currently being explored, such as heat from rivers, the London Underground, and sewers; waste heat from industrial processes; and hydrogen fuel cells. Once the heat network is in place the system is ultimately very flexible. Whilst gas-powered CHP engines are the most common generators now, that could all change in the future and energy centres can be updated to take advantage of new knowledge and new technology.

Some experts predict that by 2030, district energy networks could be providing 10% of the UK’s heat. Given the flexibility that district energy offers, this may be an under-estimate. It truly is a future-proof solution to community heating needs.