Replacing inefficient night storage heaters with ground source heat pumps in twelve bungalows housing older residents in rural Cornwall; this five-time award-winning scheme is the first shared ground loop ground source heat network project undertaken by Coastline Housing and also the first of its kind in Cornwall.
LocationWheal Vyvyan, Constantine, Cornwall
Completion DateAug 2016
Key Facts
x12 bungalows housing older residents
x11 Economy 7 electric heaters and x1 oil boiler replaced
x3 groups of 2 boreholes – each group serving 4 dwellings
An individual 3kW Shoebox heat pump housed in external enclosures next to the front door serving each dwelling
Non-Domestic Renewable Heat Incentive (RHI - this scheme has closed), Central Heating Fund (CHF) & ECO grant
New hot water cylinder and radiator systems
£188 saved on heating bills per annum
Background
Coastline Housing was looking to replace inefficient night storage heaters in a group of bungalows situated off the gas grid. Coastline attended a seminar hosted by Kensa where they heard from fellow social landlord Trent & Dove Housing about their successful experience of installing ground source heat pumps into similar bungalows. This helped Coastline shape their opinion that ground source presented a credible and affordable heating and hot water option for tenants in off gas grid homes, and prompted them to undertake a trial in twelve bungalows housing older and vulnerable residents at Wheal Vyvyan in Constantine, Cornwall.
The project benefited from a combination of funding including the Non-Domestic Renewable Heat Incentive (RHI – this scheme has closed), an up-front grant from the Energy Companies Obligation (ECO) and new funding offered by DECC in the form of the Central Heating Fund (CHF). Coastline made a successful bid for the CHF money through Cornwall Council, which provided an attractive value for money opportunity when combined with the other funding streams. Therefore, it was a combination of Kensa’s successful case study portfolio and a funded proposal which led to Coastline taking this first project forward.
Solution
The project featured a micro district ground source heat network. This innovative system architecture, pioneered by Kensa, includes an individual ground source heat pump in each bungalow linked to a communal ground array. The Wheal Vyvyan estate had six communal boreholes drilled by local drilling contractor Aquasource to an average depth of 60m, feeding 12 individual 3kW Shoebox heat pumps. This communal approach reduced drilling costs and also made the project eligible for the Non-Domestic Renewable Heat Incentive (RHI – this scheme has closed), giving Coastline Housing the opportunity to receive quarterly payments from the Government for 20 years. It also ensured that each property can use their own preferred energy supplier and pay only for the heat they use, rather than more common district heating systems where it becomes necessary to meter for payment, which is more complicated for both the landlord and tenant. The system design is also exempt from Heating Metering and Billing regulations.
Kensa specified a 3kW ‘Shoebox’ heat pump to be installed in every property; the innovative Shoebox model is the smallest and quietest ground source heat pump on the market. It is the product of choice in social housing properties, as there is no requirement for external plant rooms, unlike air source heat pumps, or ancillaries, such as oil tanks, to be sited. In the case of the Wheal Vyvyan estate the Shoebox units were neatly fitted in external stores previously used for coal, with additional shelving set up over the heat pump to provide a useful storage space for tenants.
The bungalows are occupied by older and vulnerable residents, who remained in their homes throughout the installations with work tailored to the individual circumstances of each tenant, for example fitting around carer visits. A high level of customer liaison was carried out by Kensa and Coastline Housing prior to the work commencing and tenants were kept informed throughout the installation process. Internal works on heating systems were provided by Coastline’s partner heating contractor Blue Flame and overseen by Kensa. The installations were carefully planned and carried out seamlessly over a six week period, which required dedicated and stringent project management. The drill rig was able to be positioned in a small area, minimising disruption during the drilling of the boreholes, and Kensa ensured any disturbed ground was fully restored.
Testimonials
Tenants have been very happy with their new ground source heat pumps, and Coastline will monitor their performance and tenant fuel bill savings as the weather turns colder in the autumn. On average tenants have each saved £188 per annum following the ground source heat pump installation compared to the previous electric economy 7 systems.
Resident Ms Osnebury commented:
Mr & Mrs Pellowe commented:
Wendy has been in her property for 18 months and thinks that the ground source heat pump is a big improvement on the night storage heaters. She said:
Chris has lived at Wheal Vyvyan for nearly 8 years. He said:
Ralph Retallack, Energy Efficiency Manager at Coastline Housing said:
Simon Lomax, Managing Director of Kensa Heat Pumps said:
Due to the success of this project, Coastline is considering undertaking ground source installations on a larger scale to provide more energy efficient homes and lower bills for its customers, and is currently working with Kensa to scope out a second ground source heat pump project.
Winner: Best contribution towards the creation of a sustainable energy economy (Cornwall Sustainability Awards 2017)