Glasgow-based Star Renewable Energy has won a £350,000 contract to supply heat pumps for a pioneering renewable energy scheme which will, for the first time in the UK, see solar thermal panels being used to power a district heating scheme.

Under the contract Star will design and build a large-scale heat pump system connected to a solar energy farm to be built in the new town of Cranbrook, now under construction near Exeter.

The system will provide heat and hot water to the town’s district heating scheme, one of the largest in the country, operated by German energy giant E.On.

David Pearson, director of Star Renewable Energy, told the Sunday Herald that the demonstrator project – awarded a £1.3 million research grant from the Department of Energy and Climate Change earlier this month – would help prove that heat pumps can be used effectively with low carbon solar panels.

A successful system would allow Crankbrook's currently gas-fired system to lower its emissions.“The aim of the project is to improve the performance of heat networks and to demonstrate how the combined technologies can replace or work alongside the existing combined heat and power district heating scheme to provide lower cost and significantly lower carbon heating and hot water,” Pearson said.

Although solar thermal panels are used to produce commercial scale energy in Denmark and Germany they have yet to catch on in the UK beyond small-scale domestic installations.

Most solar energy schemes in the UK use photovoltaic cells that convert heat from the sun into electricity. Solar thermal panels, by contrast, work by harvesting solar heat from water circulated through the panels.

As part of the project Star will install a high-temperature heat pump that will draw heat from approximately 2,000 square metres of ground-mounted solar thermal panels.

The panels will produce hot water at 55 degrees during the day and Star’s heat pumps will boost the water temperature to 80 degrees overnight, when off-peak electricity is cheap. This will allow the system to meet peak demand for energy in the morning.

“Although the pumps will use electricity as part of this process, some of which could come from rooftop photovoltaic cells rather than from mains power, we will end up producing five units of heat for every unit of electricity used,” Pearson said.

A network of super-insulated underground pipes will deliver the harvested heat and hot water to 3,500 new homes in Cranbrook being built by Taylor Wimpey, Persimmon and Bovis, as well as to the nearby new £210m Skypark industrial estate.

The contract to build heat pumps for the Devon project is seen as a breakthrough for Star Renewable Energy, being the first contract it has won since being spun off in 2013 from £43m-turnover Star Refrigeration Ltd, the UK’s largest industrial refrigeration contractor.

The decision to create a division focussed on heat pump technology was made in the hope that the heat pump market in the UK and abroad would take off, but so far contracts have been elusive.

In 2010, before the split, Star installed an internationally high-profile £5m heat pump in the Norwegian city of Drammen which produces 14-megawatts of clean energy from seawater in a nearby fjord. Since then Star has provided heat pumps for 14 other projects in Europe, of which three were in the UK.

The UK contracts including installing heat pumps at a Nestle factory in Halifax and in the exclusive One Hyde Park residential development in London’s Knightsbridge, where Star’s heat pumps are used to harness heat from an underground aquifer.

“Unfortunately the market for heat pumps over the last two years has been very slow and very stubborn so we are pleased to get the Cranbrook contract,” Pearson said. “We have been pushing for seven years on heat pumps and are hoping that this will be the first order of a new era.”

“Although the Drammen project involved using heat pumps at 90 degrees, none of the heat pumps in the UK currently operate above 50 degrees so this project in Devon will also be important as it will show that we can operate heat pumps at temperatures up to 80 degrees.”

Construction work on the heat pumps for Cranbrook is now under way at Star’s Glasgow factory and Pearson expects the system to be up and running by the end of the year.

The demonstration scheme will run until March 2017, after which a progress report will be submitted to the government on how the technology pioneered at Cranbrook could be rolled out to existing and new-build district heating schemes around the UK.

Some of those potential future projects could be in Scotland but as solar radiation levels in southern England are roughly 30 per cent higher than north of the border, Pearson believes that most of the work for solar-sourced heat pumps will be in England, Wales or abroad.

“Heat pumps were first spoken about in 1852 by Lord Kelvin in a lecture at Glasgow University but are only now coming to life in a commercial sense and we now have the skills to make this a modern energy revolution,” he said. “I wonder what Lord Kelvin would make of it all these years later.”