Heat pumps work for me - but they're not yet a money saver

## Summary
In a recent year before the heat pump installation, the house consumed a total of 28,000 kWh, which would mostly have been gas heating. Evan Davis met the Boyntons whose heat pump works by cycling refrigerant through a loop, going from hot to cold and gas to liquid to generate heat I still find it hard to get my head around the fact that you can take heat out of the air at -5C, to help warm water up to 50C. He's used a heat pump for 20 years, but thinks companies need to be honest about their limitations. "The typical experience is coloured by the fact that heat pumps make colder water than gas boilers, and if you don't change your radiators your house will be cold," he says. Greg Jackson, the chief executive of Octopus - the biggest retail energy supplier in Britain and the biggest vendor of heat pumps too - is enthusiastic about the technology. "[We install] around 1,000 a month, typically," he says. "There's still quite a lot of policy barriers, but people who get them are very, very happy." But he accepts the "crazy high" price of UK electricity is a problem. "In the UK, currently, electricity is about four and a bit times more expensive than gas.

## Article Content
Heat pumps work for me - but they're not yet a money saver
10 minutes ago
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Evan Davis
Presenter on Radio 4’s PM
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BBC
I know that not everybody is interested in the precise form of plumbing by which they heat their home, but it's a topic I've become obsessed with. That's partly because I have a French husband and we bought a very old, leaky house in northern France some years ago, which already had a heat pump installed.
I had never encountered one before. Quickly, it became apparent that the heat pump didn't work properly, but fortunately it was under guarantee and once it had been replaced it worked very well indeed. In fact, we went on to buy a second one for our loft extension.
The other reason I'm interested in this topic is because I'm excited by the prospect of witnessing a historic change - a horses-to-cars type moment. Since the stone age, people have typically kept themselves warm by burning things - wood or coal on a fire, or oil or gas in a boiler. A society-wide shift to electric heat pumps would mark a transformation to a whole new way of creating heat in the home.
This government wants Britons to embrace heat pumps (as did the last). But it's a shift that comes loaded with complicated questions in a country where electricity costs so much. Currently they're more expensive than a gas boiler to install, and can also end up more expensive to run. As a result, they're mostly aimed at the environmentally-conscious and better off.
The question is: can the figures ever add up so that it saves the average consumer money? And in a country where gas is so embedded as the norm, are heat pumps really the right technology for a greener future?
The happy family
Emily and Stephen Boynton, who live in a leafy London suburb, decided to install a heat pump in their four-bedroom detached home during the pandemic. Emily had just turned 50 and was reflecting on life, her future, retirement, the environment - all sorts of questions.
"If you've got the money to do it, and you've got the space, then you should probably get on with it," she says now of her decision to buy a heat pump.
Installing one likely involves some new pipework, and often new radiators; it is not something you can just get one day when the gas boiler packs up. Emily and Stephen had decided to renovate their kitchen, so it was a good opportunity to get some disruptive work done.
They have a big
air source
heat pump outdoors. It works with heat in the air, hence the name. It warms water which flows through buried pipes going indoors, feeding the radiators as well as their new underfloor heating in the kitchen.
Stephen and Emily Boynton installed a heat pump in their four-bedroom detached house
Emily is the one who looks after the spreadsheets - and she shows me the cost. Like many customers, before installation they were advised to improve their insulation. That's because, as we will see, heat pumps usually provide a more gentle heat than gas boilers. That came to £5,000. Then they paid for the heat pump itself, and the under-floor heating.
In total they spent £17,000, though in return they received a £5,000 government grant.
It's a big capital sum. To put it another way, if you were to finance the cost by piling £17,000 on to a 25-year mortgage, at a 4.5% interest rate, your extra monthly mortgage payments would be about £100.
But then Emily showed me the spreadsheet where she has tracked their energy use, measured in kilowatt hours (kWh). In a recent year before the heat pump installation, the house consumed a total of 28,000 kWh, which would mostly have been gas heating. In the latest year, they used just 10,000, despite having had some adult children move home in that time. In other words, they've cut their energy use by almost two-thirds.
"I guess that reflects how much more efficient the heat pump is and also the impact of the insulation," Emily says.
Now, that is worth remembering - especially when you hear people pour vitriol on the whole idea of heat pumps. This technology delivers almost magical levels of energy reduction. They may be the subject of - pardon the pun - heated debate, almost religious in its fervour. But heat pumps are already used in hundreds of thousands of homes in the UK, and tens of millions across Europe. And it is not hard to find contented heat pump customers.
The science bit
So how does a heat pump heat? And how does it save energy?
A heat pump basically runs a chemical -
the refrigerant
- round and round in a closed loop, going from hot to cold, gas to liquid, compressed to decompressed. Rinse and repeat.
At one end of the loop, when the refrigerant is in the form of a gas, the heat pump compresses it to make it super hot (rather as a bicycle pump heats up when you use it). Then it can use that heat to warm up water to run through your radiators.
As the gas gives its heat to the radiator water, it condenses into liquid form; this liquid then passes through an expansion valve (the decompression)

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## Expert Analysis

### Merits
- Evan visited "Energy House 2" at the University of Salford, a climate-controlled, "Truman Show-like" environment to test heat pumps Faced with a chilly house, some users might then dial up the power on their heat pump - but if you do that, much of the efficiency advantage fritters away, he says.

### Areas for Consideration
- A different kind of heat There is an issue though.
- When it comes to whether heat pumps make sense as a wider national strategy, the big challenge comes down to some basic maths.
- Greg Jackson, the chief executive of Octopus - the biggest retail energy supplier in Britain and the biggest vendor of heat pumps too - is enthusiastic about the technology. "[We install] around 1,000 a month, typically," he says. "There's still quite a lot of policy barriers, but people who get them are very, very happy." But he accepts the "crazy high" price of UK electricity is a problem. "In the UK, currently, electricity is about four and a bit times more expensive than gas.

### Implications
- The other reason I'm interested in this topic is because I'm excited by the prospect of witnessing a historic change - a horses-to-cars type moment.
- As a result, they're mostly aimed at the environmentally-conscious and better off.
- And in a country where gas is so embedded as the norm, are heat pumps really the right technology for a greener future?
- Emily had just turned 50 and was reflecting on life, her future, retirement, the environment - all sorts of questions. "If you've got the money to do it, and you've got the space, then you should probably get on with it," she says now of her decision to buy a heat pump.

### Expert Commentary
This article covers heat, pumps, pump topics. Notable strengths include discussion of heat. Areas of concern are also raised. Readability: Flesch-Kincaid grade 0.0. Word count: 2343.