09/04/2014 | Gary Hartley | Products and technology, Green strategy and politics | air-source heat pump, DECC, District heating, Ed Davey, ground-source heat pump, heat pumps, mapping, technology field trials, Thames, water-source heat pump
Renewable heat is in the news more than ever, with energy security issues like the Russia-Ukraine crisis piquing interest in the energy we can generate right here. Even a less talked about technology has got column inches of late – the water-source heat pump.
The government is mapping the potential for water-source heat pumps, and the Energy Secretary, Ed Davey, recently visited a riverside development in Richmond, South London. The district heating scheme uses a heat pump in the Thames to provide hot water for a substantial complex. He spoke effusively of it as an illustration of potential:
I think this exemplifies that there are technological answers which will mean our reliance on gas in future decades can be reduced. Here you have over 100 homes, you have a hotel with nearly 200 bedrooms and a conference centre that won't be using gas.”
Water source heat pumps can use heat from rivers, lakes, in fact any body of water heated by the sun. Big claims are clearly being made about the technology, but a slight note of caution might be required – or perhaps cautious optimism.
The first phase of our field trial of ground and air-source heat pumps in a domestic settings found that in a number of cases, systems were not performing as well as they could be. Our second phase delved deeper into the reasons for performance variations, and resulted in significant changes to installation guidelines, in consultation with the government. This is change that we hope will be clearly seen by those installing heat pumps when the domestic arm of the Renewable Heat Incentive (RHI) is introduced.
This kind of valuable learning does suggest that as well as mapping potential, it would be a very good idea to enter into some scientifically-rigorous trials of water-source heat pumps in district heating scenarios in the UK, and indeed on a smaller scale.
It is also worth mentioning that heat pumps are not some kind of space-age technology. In fact, London’s Royal Festival Hall was using a water-source heat pump in the Thames to heat its premises back in 1951!