When thinking about installing a heat pump, the financial benefit is always at the forefront of the specifier’s mind. With the recent launch of the Domestic Renewable Heat Incentive (RHI), there has never been a better time for self-builders to consider solutions such as ground source heat pumps in their project.
Launched in April this year and aimed at promoting large-scale uptake of renewable heating technologies, the RHI quite simply guarantees to pay an attractive income for all the renewable heat generated for a period of seven years. Coupled with the energy cost savings made against standard central heating options, self-builders can now expect a typical ground source heat pump to realistically produce a payback in around five years or less and provide a tidy profit in return.
While the scheme covers a range of renewable heat technologies, ground source heat pumps offer a number of distinct benefits: less visually intrusive than other options available, exempt from additional planning permission restrictions, quiet in operation and above all, heat pumps deliver the lowest annual energy costs for heating and domestic hot water.
For ground source heat pumps, the RHI pays an income of 18.8p/kWh for the renewable proportion of the energy needed to provide heat and hot water to your home. How much that will mean to a self-builder will depend on a number of factors, but ultimately comes down to the calculated energy consumption of the self-build and the efficiency of the system.
Ideal for well insulated, low energy buildings, ground source heat pumps work most efficiently with underfloor heating, as heat can be distributed across a large surface area at a low water temperature. This suits ground source heat pumps well, allowing them to work to their optimum efficiency, a fact that will be represented by both lower running costs and a higher RHI payment – as a higher proportion of the heat will be coming from a renewable source.
That isn’t to say that heat pumps can’t work effectively alongside radiators, or when used to produce hot water. Indeed, for practical reasons, heat pumps almost always provide hot water as well as heating and many designs employ underfloor heating downstairs and radiators on upper floors. The slightly higher water temperatures required simply mean that RHI payments will be affected slightly.
To help calculate what the RHI could do for your self-build, Kensa, a leading UK manufacturer, produced a handy online tool to provide crucial information about the costs and how much you could make and save by installing a ground source heat pump. It will also tell you what size system you are likely to need and how much land area you are likely to require. Ultimately, the outcome for any self-builder is likely to be compelling.