Domestic Renewable Heat Incentive tariffs - have changed over the years

The RHI tariff for GSHPs started at 18.8 pence/kWhr in 2014.
It has risen with inflation to 20.46 pence/kWhr.

RHI for ASHPs was introduced at 7.3 pence/kWhr in 2014.
It has risen to 10.49 pence/kWhr.

The RHI tariff for biomass started at 12.2 pence/kWhr in 2014.
It has since been "degressed" down to 3.85 pence/kWhr,
before rising to 6.74 pence in April 2018.