Harvesting hot water from our fields

With much of the focus for solar technology on photovoltaics Technology4Change spoke to BRE expert Robin Wiltshire about the potential for solar heat networks. Robin chairs the International Energy Agency’s district heating and cooling energy programmes.

Research by the International Energy Agencyn into using lower delivery temperatures of as low as 50°C opens up opportunities for greater use of locally available waste heat and the application of solar thermal technology at the district level.

“There are already successful pilots in places like Denmark that we can learn a lot from” says Robin.

Typical early flagship projects such as those at Marstal and Braedstrup incorporate 75,000 m3 thermal storage pits to store excess heat. The heat is stored centrally and distributed across the community when required. Robin sees potential for these systems to operate in smaller, rural locations as opposed to the traditional heat network applications in built up areas.

The lower temperatures open up new research challenges such as the issue of legionella (a pathogenic group of Gram-negative bacteria) and the IEA association includes experts who are looking at robust solutions to ensure the safety of the technology.

The next phase for the IEA group is to look at how existing heat networks could be adapted to operate at lower temperatures, helping solve the energy trilemma of carbon, cost and security.

Robin is keen to explore the UK potential for the technology. “It would be great to find a community in the UK to take up the baton and help us develop the UK’s first solar thermal field.” Robin’s research is also looking at the applicability of district heating to rural locations and their integration into smart communities.

This article, including the image, has been adapted from an article published by Technology4Change.