District heating a ‘game changer’ for economics of SMRs

The potential to provide low-carbon heating through district heating networks is a “game changer” for the economics of small modular reactors, the Energy Technologies Institute has told Utility Week.

By using the two in combination, the revenues from small modular reactors (SMRs) could increase by between 40 and 60 per cent.

The ETI has calculated that SMRs could make as much money from selling heat as they could from selling power, according to its strategy manager for nuclear Mike Middleton. 

As optimising the reactors for the generation of combined heat and power would lead to a 20 to 30 per cent reduction in electrical output, this would translate to a 40 to 60 per cent increase in overall revenues when compared to reactors only generating electricity.

Larger nuclear plants have already been connected to district heating networks, although not many of them. “You only have to look to somewhere the Besnau nuclear power plant in Switzerland where they do exactly this, and they’ve done it for decades,” said Middleton. “Their Refuna district heating system goes out into the countryside for tens of kilometres delivering heat supply to homes energised with nuclear power.”

However, larger plants are not ideally suited to district heating. They are typically sited relatively far away from major population centres, and even if they were sited nearer “there are relatively few places in the UK that have a got a heat demand big enough to eat the thermal output from a [European Pressurised Reactor]” – the type which is planned for Hinkley.

“[SMRs] have got a more flexible approach to siting,” Middleton added.  “I’m not talking about putting them in cities. I’m talking about even with the existing siting criteria, you can find sites to put SMRs where you can’t put big plants.

“Their thermal output is such that they’re a much better match for the amount of heat that will be required by city-scale district heating systems.”

Public perceptions of nuclear will be one of the biggest barriers to using SMRs for district heating, according Tony Roulstone from the Department of Engineering at the University of Cambridge. “I think that the public’s not ready for it yet,” he told Utility Week. “It’s quite a hill to get over.”

Earlier this month the Department for Business, Energy and Industrial Strategy accidentally published for a few hours the list of eligible participants for the first phase of its competition to find the “best value SMR design for the UK”.  A roadmap for the development of SMRs is due to published by the government once the first phase is complete.