Sixty homes in Oxford’s Blackbird Leys will be the first to have low carbon ground source heat pumps installed as part of Energy Superhub Oxford (ESO), the major energy infrastructure project which aims to lower carbon emissions across the city. The heat pumps are to be installed by Kensa Contracting into homes managed by affordable housing provider Stonewater.
Kensa Contracting will be installing in the homes its Shoebox ground source heat pump system, which is designed to fit comfortably inside properties and provide all of a household’s heating and hot water needs. It generates heat at the point of use, emitting no carbon dioxide nor air pollution. Heat losses, which are common with district heating schemes, are also eliminated. Each Shoebox heat pump is connected to an ambient shared ground loop array, and generates its own electricity bill to provide heating independence for residents, along with lower heating bills.
First to be installed will be the ‘ground array’ linking the properties, which Dr Matt Trewhella, managing director of Kensa Contracting, explains is “a series of 130m-deep vertical boreholes containing pipes to extract heat from the ground. These are connected together and then pipes run to each property to give a heat source for each heat pump.” The company claims that this stage should take around 8-12 weeks, and will be followed by installing the new heating system and the heat pumps.
The installations were due to begin in April but have been delayed by the national lockdown caused by Covid-19. At the time of writing, Kensa Contracting had ‘very provisional’ dates to commence the work pencilled in for June, or when it can operate safely and within government guidelines for social distancing.
Engagement with residents has also been disrupted by the Covid-19 crisis. “We had a meeting booked in a village hall on 23rd March to meet residents face-to-face, give a visual presentation and allow them to ask questions,” said Trewhella. “This had to be cancelled due to Covid-19, especially as a large number of the residents were in risk categories, so we haven’t yet had the opportunity to obtain detailed feedback from them.”
Kensa Contracting had however already informed residents about the work by booklets explaining the process and have spoken to some by phone.” So far the reaction has been positive,” reported Trewhella, “although several commented that ‘anything is better than night storage heaters’ and they might have been just as pleased to get any sort of proper heating system. Hopefully once we get to meet them and they see the work happening, they will start to appreciate the work involved and the benefits of the ground source heating system.”
The £42 million ESO project which aims to decarbonise power, heat and transport across the city, plans to roll out ground source heat pump technology to a total of 300 properties around Oxford over the next two years. The project also includes installation of ‘the largest hybrid battery ever deployed‘, a 50MW grid-scale battery in an electricity substation in Oxford’s Cowley, creating a new connection to the national grid and powering a 10km network of electric vehicle (EV) charge points as well as the ground source heat pumps in homes. ESO is led by Oxford City Council and Pivot Power, and includes Habitat Energy, Invinity Energy Systems (previously redT energy), Kensa Contracting and University of Oxford.