UK: The district energy renaissance

Date: 24 November 2014

As the uptake of district energy rises, more urban areas can future-proof their energy systems. However, challenges do remain as explained by Simon Woodward, Chairman at The UK District Energy Association…

District Energy is in renaissance, if you recall the many dozens of networks that used to exist in the 1960’s/70’s, or if you do not remember those old schemes you will see it as a new solution which is currently bursting onto the UK heating and cooling market as the golden bullet to solve low carbon heat supplies in dense urban areas. Either way, it is a method of delivering low carbon energy which is clearly seeing a considerable increase in uptake in the last two to three years.

However, there are still barriers to implementation which include high initial capital costs, lack of understanding of how to design networks, apart from a few specialists, and almost no fiscal support for the implementation phase.

Fortunately, the situation is changing. As the uptake of district energy (district heating and/or cooling) rises, the market expects installation prices to fall as new entrants move into the industry and increase competition.

There are steps being taken to introduce codes of practice and training and considerable attention is now being drawn to the issue of secondary network losses in new build residential developments. This is particularly a problem where a lack of thought has been put into the design of the heating network from the point it enters the apartment block, up to each dwelling. With unit dwelling annual heating and hot water consumptions in the region of 4,000 kWh or less, the amount of energy lost in transmission of that heat to the dwelling is becoming proportionally higher and a major issue. Consultants are solving this by ventilating risers and even in some cases I have heard of air conditioning being added to overcome the overheating problems resulting from these heat gains. However, in reality sensible network design including routing, levels of insulation and operating temperatures can do much to reduce these losses to acceptable levels, removing these rather cumbersome engineering solutions to a problem which should not exist.

What is certainly true is that once an urban area has a district energy network, it has essentially future proofed its energy system. When the initial source has reached the end of its useful life, e.g. gas fired CHP, then other energy systems such as localised energy from waste, waste heat recovery or other LZC emerging technologies can then be bolted into this network to effect an “energy generation heart transplant”.

However, the industry still needs support to deliver this expected level of growth. Detailed analysis of every urban area in the UK carried out by the UK District Energy Association demonstrated that it would be realistic to take the percentage of homes connected to a network from 2% to 14% by 2050. This analysis however assumes the implementation of a low carbon heat network incentive sitting alongside the RHI. The government is currently considering a RHI Network Uplift – which is fantastic news – but as many schemes currently being delivered are using gas fired CHP as their initial source, this will not apply, requiring further work.

There has been an impressive number of over 80 local authorities taking up DECC’s Heat Network Delivery Unit (HNDU) funding, to explore the feasibility of a network in their area. However, as the former Head of the HNDU commented at the 2014 UKDEA AGM, the success of the HNDU will not truly be judged by the feasibility funding it has awarded, but by the pipes which are being installed as a result of that funding in four years’ time.

Coupling this HNDU funding with the GLA’s push for heat networks in all new developments across London means that it is clear that the district energy landscape will be very different in 2018 from where it is today, the question is just how different.

 

Simon Woodward, Chairman

The UK District Energy Association