Monday, 22 February 2021

Renewable heat installation rates

A friend asked me if I think that heat pumps are still a 'niche' technology or are becoming mainstream. She was surprised by the number of companies able to install in this area - the MCS website finds ten within 30 miles of Cambridge. So I took a look at the statistics for take up of the renewable heat incentive for heat pumps (domestic). Here is a chart showing cumulative installations.

Domestic Renewable Heat Incentive cumulative applications by month, data from [1]. The steep rise up to April 2015 includes legacy applications.

There is an uptick in the rate of applications in 2019/2020, before the pandemic hit, then not much happened for a while followed by a strong recovery from October 2020. Over the last four months there were approximately 1000 applications/month. There were also about 130 applications/month for ground source heating pump and just 43/month for biomass boilers.

Heat pump installations is still a tiny fraction of boiler replacements.

The application rate for ASHP has more than doubled since 2018. However, given that there are around 25 million homes with gas or oil central heating in the UK (as of 2017 [2]) there must be about 140,000 gas boiler replacements each month. That means ASHP installations account for about 0.7%. There is a lot of catching up to do.

Specialist tariffs, and smart controls make heat pumps cheaper to run.

The growth in the heat pumps market is accompanied by the appearance of some specialist electricity tariffs which can make them cheaper to run. For example, Good Energy has a heat pump tariff and there is a new thermostat called Homely which optimises your heating schedule against variable tariffs such as Octopus Agile. Hybrid heat pumps (with a backup boiler) are also just starting to gain visibility. EDF Energy has a special offer on these, with smart controls to optimise use of heat pump and boiler, though only for homes currently using oil.

What is the best solution for your home?

Could you install an air source heat pump instead of a boiler in your home? Generally speaking, your house needs to be well insulated first. Does it keep its heat overnight (dropping not more than 2-3°C?). Can you keep the house warm running the radiators at only 45°C ? Do you have a space to put the heat pump, usually at the rear of the house? If so, then a heat pump may well supply your needs. If not, there are various options but which is best depends on the circumstances. I will be talking about this on 23rd March for Transition Cambridge. If you want to read more about heat pumps before then, try the Transition Cambridge Heat Pumps FAQ.

[1] Renewable Heat Incentive Statistics (

[2] The Housing Stock of the United Kingdom (BRE) 2020

1 comment:

  1. The RHI Applications curve for Air Source Heat Pumps certainly looks steeper towards the end of 2020 compared with pre-lockdown. Disappointing that so few boiler replacements still are not taking advantage of heat pump technology, particularly with the extension of RHI funding to March next year.

    I wasn't aware of the special heat pump tariffs being offered by electricity providers. I'll have to look into that.


Comments on this blog are moderated. Your comment will not appear until it has been reviewed.