Ofgem has issued new guidance on Renewable Heat Incentive payments for ground-source heat pumps.
Until now there has been confusion over how to calculate RHI payments for systems that cool as well as heat a building, as during the cooling process heat is returned from the building back underground for storage.
Ofgem is now recommending an approach, first suggested by the Ground Source Heat Pump Association, that acts as a “ready reckoner” of the amount of “first time” heat extracted from the ground.
72.3 per cent of the kilowatt hours of heat produced will qualify for RHI payments for GSHP heating and cooling systems if the system is smaller than 100 kW; for systems larger than that, the figure 64.7 per cent.
If a GSHP system is for heating only, 100 per cent of the heat produced will qualify.
The advice spells out how owners of GSHP systems that both heat and cool a building can confidently apply for payments from the government’s flagship scheme for renewable energies.
The figures were arrived at by comparing the average efficiency of a heating-only GSHP with the efficiency of a heating-and-cooling GSHP system, and working backwards.
Ofgem commissioned independent technical consultants who validated the approach. The method will be reviewed within a year.
While Ofgem has written to many stakeholders recommending the approach, it is not binding on applicants, who are free to submit RHI applications with alternative calculations for mixed heating and cooling systems.
GI Energy has welcomed the new guidance issued by Ofgem.
GI Energy development director Chris Davidson said: “This is good news for organisations and individuals who want to install ground-source heat pump systems to heat and cool their buildings.
“Instead of having some complicated formula, or having applications held up in processing, the guidelines recommended by Ofgem are simple, easy to apply and clear.
“They will encourage people who want to take advantage of the fantastic energy efficiencies of GSHP systems.”