The changes, welcomed by ground source specialists Econic, part of Myriad CEG, offer a new way of measuring how much heat output qualifies for RHI payments.
Many Ground Source Heat Pump (GSHP) systems inject recovered or waste heat into the ground as an aid to improving system efficiency, and as it can be a cost effective cooling approach – they are termed Ground Source Heating and Cooling (GSHC) systems.
Under the RHI Regulations 2011, tariff payments for ground source heat pumps (GSHPs) can only be made for extracted heat that naturally occurs in the ground.
As a consequence, heat that is injected into the ground and subsequently extracted by a GSHC system is ineligible for support payments.
Rob Gardiner, managing director of Econic, said: “Ground source heat pumps are the most efficient renewable technology available for the provision of heating, cooling and simultaneous heating and cooling.
“Indeed, by providing both heating, cooling and simultaneous heating and cooling, it encourages more efficient system designs.
“This was not the case with the scheme prior to this announcement from Ofgem. Until now it has been difficult for RHI applicants to quantify this ineligible heat in order to exclude it from the eligible heat generation for which they are seeking payments.”
The announcement from Ofgem is very welcome and now puts ground source heat pumps with parity against other renewable technologies with respect to payments for the provision of cooling.
“Thankfully now, following the intervention of the Ground Source Heat Pump industry, key stakeholders and GSHP industry businesses, a new system has been validated to help work out payments.”
The method uses the system’s Coefficient of Performance (CoP) – the ratio of heat output to operating energy input of a heat pump – as an estimate of ineligible heat output.
Coefficient of Performance (CoP) values of 3.07 for Heat Only systems and 4.63 for Non-Heat Only systems have been recommended for use in calculating the following proportions of heat eligible for payments.
- Heat Only – 100% of generated heat
- Small Non-Heat Only – (<100kWth) 72.3% of generated heat
- Large Non-Heat Only – (>100kWth) 64.7% of generated heat
Rob Gardiner added: “Owners of accredited installations are entitled to receive payments based on this agreed percentage of eligible heating and cooling output for the duration of their participation in the RHI scheme, which is great news and offers a lot more clarity for customers seeking payments through the RHI.”
The system is to be reviewed after one year, or at such time as Department for Energy and Climate Change (DECC) may amend the Regulations in relation to this issue, whichever is the sooner.
More details of changes announced by Ofgem can be accessed here.