On p31 of the consultation document, it states that only efficient heat pumps will be permitted. However this ignores the fact that the efficiency of a heat pump is related to the work it is being asked to do, and not simply the manufacturing standard. The standard CoP (Coefficient of Performance - the higher the figure the better) figures used by heat pump manufacturers refer to an uplift of 35°C. For every 1°C above this that the system is required to deliver, the efficiency of the heat pump system reduces by around 3%. Therefore a heat pump may have an efficiency of 4.0 when delivering hot water at 40°C (suitable for underfloor heating) but this will reduce to less than 2.0 if used to heat radiators at over 70°C. If the published efficiency of the heat pump starts at 3.0, then the actual efficiency is likely to fall below 1.5 if used to heat conventional radiators.
A heat pump needs to perform at a CoP better than 1.5 in order to match the carbon output of an A rated oil fired boiler.
As it stands, this incentive will cause oil-fired boilers (as a technology) to be abandoned, without any clear justification. Many people with radiator-based central heating systems looking to replace a boiler will be tempted to switch to a heat pump solely because of the incentive, which looks like it's going to worth around £750-£1,000 a year for 18 years. And yet, unless the heat delivery system is changed (which is unlikely because it would be expensive and disruptive), the energy and carbon burned will actually increase, compared to an A rated oil-fired boiler. For this reason, air source heat pumps, in particular, are ill suited to replacing domestic boilers. There seems little logic in incentivising people to install them instead of efficient fossil-fuel boilers.
Bearing this in mind, why shouldn't this incentive scheme be extended into areas where it has the capability to make a much more meaningful contribution to reducing carbon emissions? How about extending it to people undertaking significant energy efficiency upgrades, way beyond topping up loft insulation and adding cavity wall insulation? The cost bringing a 20th century (or older) house up to modern standards (something akin to the Passive House standard for refurbishment, or Energy Savings Trust A rating) is far greater than the cost of installing a heat pump. Estimates vary from around £12,000 up to £40,000 (if glazing is to be included as well). The carbon savings are also much greater, however there is no financial incentive other than making savings on fuel bills. As it stands, the payback on this type of work extends to many decades.
The UK Green Building Council is putting forward a Pay As You Save Scheme, whereby lenders will be encouraged to make loans to undertake such improvements and in exchange the repayments would be paid for from the savings from lower fuel bills. Such a scheme enjoys no official backing as yet. Why not add some element of subsidy to it by adding such refurbishment to list of "technologies" which the Renewable Heat Incentive is designed to reward?