Opinion

Heat pumps in the headlines again – but what is the truth?

The front-page headline in the Sunday Telegraph on 22nd August 2021 read ‘Heat pumps do not work as well as gas boilers, admits Kwarteng’, as reported by Edward Malnick, Sunday Political Editor. Apparently the ‘new’ green heating technology is ‘still in its infancy’.

Laura Bishop, chair of the GSHPA talsk about heat pumps article

These kinds of headlines grab the public’s attention and, even if fundamentally incorrect, still spread misinformation and concern amongst the general public about heat pumps, whose trust the heating industry needs to win over if we are to achieve our legally binding Net Zero targets by 2050.

In order to address this misinformation Renewable Energy Installer spoke with Laura Bishop, chair of the GSHPA, who gives us the facts behind the article’s claims in the piece below:

As a chartered mechanical engineer of 21 years, 10 of those working on heat pump deployment in many and varied applications, I base my views and opinions on fact and experience. However, whilst frustrating to read, articles such as this do give an opportunity to respond with said facts and I have drawn out a couple of the main comments below for response.

Claim: “Whole gas boilers had been refined over many years, heat pumps are still in their infancy.”

Incorrect. The first heat pump system was invented in around 1857 with the first ground source heat pump being invented in 1948. Heat pumps have been used for heating and hot water in Scandinavian and other European countries for many years, where the climate is considerably colder than ours. The graph below shows heat pump deployment in other countries since 2010 with the UK languishing at the bottom. Maybe lack of visibility in the UK leads to a notion that heat pumps are still new.

Comparison of heat pumps 2013-2020
Figure 1 Comparison of heat pump installations 2013 – 2020 France, Germany, Italy and UK. EHPA European Heat Pump Market and Statistics Report – 2020

Statement: “I don’t think heat pumps are that much worse than boilers. All I’m saying is that they could be improved if there was more investment.”

It’s not clear what the comment ‘much worse than boilers’ means. Efficiency or performance? Best performing seasonal efficiency of a correctly installed condensing boiler is around 93%. Seasonal efficiency of a ground source heat pump is anywhere between 300% – 500%, depending on temperature needed in the building and the type of heat pump deployed. Or is it temperature delivered? 80°C from a gas boiler vs 55°C from a heat pump? Heat pumps can deliver 35°C – 85°C, depending on the type of heat pump deployed. But we only need 18 – 21°C room temperatures in our homes. A correctly designed and installed heat pump system including correctly sized radiators will outperform a gas boiler in terms of efficiency and match it in terms of thermal comfort.

A comment further down the article states ‘gas heating can pump 60°C into radiators….heat pumps will operate at 50°C’. I don’t know where to begin with this as both gas boilers and heat pumps can operate at different temperatures – the end goal is achieving the right temperature in a room. What has this to do with 60 or 50°C? Just arbitrary numbers pulled out of the air by Mr Malnick? This is either poor understanding or poor journalism. Either way, misinformation is spread by journalists using articles such as this.

Statement: ‘Different types of green heating solutions will be appropriate for different types of properties.’

This I do agree with – no one size fits all approach. But heat pumps can be deployed in more properties than many people think and without the major internal refits that are discussed on a regular basis.

I could go on but wordcount prevents me. However there is one more important comment to address on ‘costs falling quickly as firms begin to invest in alternatives to gas boilers.’ While this may be true, due to volume deployment, it is the low cost of gas vs the high cost of electricity that is the real stumbling block in the UK. This blocker must be addressed if we are to attain the 600,000 heat pumps per year by 2028 goal from our Prime Minister.