Non Domestic RHI funding can be secured for retrofit and new build domestic properties where district ground source heat pump systems are utilised.
Not only do ground source heat pumps offer a highly efficient and cost effective renewable heating solution – getting seven years’ of guaranteed payments from the Government’s Domestic Renewable Heat Incentive (RHI) scheme to offset the initial investment cost is an added bonus.
However, ground source installations don’t always follow the typical ‘one heat pump, one ground array’ route commonly seen on the Domestic RHI tariff. Where there are multiple buildings on one site all requiring heating and hot water, a district ground source heat pump system architecture can provide a low cost and ultra-efficient solution, especially if the site has no access to mains gas.
And better still, these types of projects can qualify for significant financial returns from the Non Domestic strand of the RHI. The current Non Domestic tariff for ground source is very generous, offering quarterly payments of 9.1p/kWh on the first 1314 hours of eligible energy produced, followed by 2.7p/kWh on any additional heat produced over a 20 year period.
District ground source heat pump systems explained
Although common in commercial projects, it is less widely known that the lucrative Non Domestic RHI funding can also be secured for retrofit and new build domestic properties where a district heating system architecture is utilised.
A district ground source heat pump system features individual heat pumps in each dwelling, all fed from the same central ground array, which is sized to deal with the peak heat demand of all the dwellings combined.
Whilst district heating is hardly a new idea, it is not widely appreciated that this approach can be used for domestic projects featuring small clusters of properties. The Department for Energy & Climate Change (DECC) has confirmed that as few as two properties linked together in this way meets the requirements of a district heating system. This definition opens up the opportunity for owners of sites with a smaller number of multiple residential properties or outbuildings, being converted or built for sale or rent.
How you can benefit from district ground source heat pump systems
Paul Dennison, Sales Manager for UK manufacturer Kensa Heat Pumps, says:
“If your project features multiple buildings, you may be able to link them to a shared ground array to cut installation costs and fuel bills, whilst delivering the energy savings and benefits that ground source naturally brings. This will qualify as a district heating scheme and allow you to maximise the benefit of the Government’s RHI scheme, accessing 20 years of funding under the Non Domestic strand.”
With no need for a plant room, this solution also overcomes the drawbacks of traditional ‘central plant’ district heating systems. As each dwelling features its own individual ground source heat pump, the occupier has complete control of their own heating and hot water system. And because heat is produced by the individual heat pump inside each dwelling, there are no external heat losses which makes this system not only versatile, but also very energy efficient compared to a traditional district scheme.
Boreholes and slinkies can be sited where practical, rather than individually in gardens. Another advantage of sharing ground arrays is that as the system grows in size a degree of diversification can be applied, so the total amount of ground array can be reduced compared to individual systems.
More information on district ground source heat pump systems, including example project costs and different ground array configurations, can be found here.