Why heat pumps will never work in Britain

Heat pumps are poorly suited to British homes and the Government’s relentless drive to install them will cause “uproar” across the country, energy leaders have warned.

The controversial devices have been adopted across Europe, but ministers are warned that Britain’s “geology, weather and culture” mean they will not work here.

Despite watering down a range of green policies last week, the Government is still proposing to ban the sale of new oil and gas boilers by 2035, part of a wider drive to reach legally-binding net zero goals by 2050.

It is urging households to install electrically powered heat pumps instead, but buying and installing one typically costs between £7,000 and £13,000.

Because take-up of government grants has been so poor, Rishi Sunak is now offering households even more money to agree to install one.

For now, there are fears that if heat pumps are pushed too hard on the British public there could be “significant resistance”.

Sarah Williams, deputy chief executive of gas distributor Wales and West Utilities, called the high price of heat pumps a “real challenge” for consumers, especially those on lower incomes.

She pointed to similar controversy in Germany over a ban on the sale of new gas boilers from 2024, dubbed the “heat hammer”, adding: “In the UK, any decision pushed upon consumers is likely to meet significant resistance.

“The challenge of mandating a heating system is that it’s not something that’s attractive or a status symbol, it’s simply a function of your home that you don’t think about.

“So the Government requiring 22 million homes to move to a heat pump is very likely to cause uproar across the UK.”

Heat pump rollout plans have already met fierce resistance, not least from rebellious Tory MPs. Caving to pressure, the Government has pushed back the ban on oil boilers from 2026 to 2035, and is now offering boiler upgrade exemptions to homes that are off the gas grid or that need costly electrical work to switch to a heat pump.

It comes after former environment secretary George Eustice warned that forcing 1.3 million rural households to ditch kerosene boilers would be “their own version of London’s Ulez.”

Even so, the push to install heat pumps in all other British homes remains. In 2021, the Government-funded Electrification of Heat Demonstration Project installed 742 heat pumps across the country with the pre-stated aim of proving the technology is viable in a range of properties. The study found that there is “no property type or architectural era that is unsuitable for a heat pump”. 

However, Mike Foster, chief executive of the Energy Utilities Alliance, a trade body, insists that installing heat pumps across the board is “like pushing a square peg into a round hole”.

He says the UK’s unique geology, weather and culture make heat pumps fundamentally unsuitable in millions of older, poorly insulated houses.

He said: “Because of the Gulf Stream, our weather patterns aren’t as stable as they are in, say, Poland. We’ve historically built houses to cope with this fluctuation of temperature. Our habit is to interact with the weather far more than in other parts of Europe.

“A heat pump runs at a constant temperature 24/7. But in our climate, being able to turn on a gas boiler if it gets cold makes more sense.”

Meanwhile, Dr Jan Rosenow, director at the Regulatory Assistance Project, a clean energy NGO, warns that the Government is undermining its own efforts to make heat pumps commercially viable by failing to reform the way we tax energy.

He points to the relatively high price of electricity compared to gas in the UK as a “big factor” explaining low uptake compared to the rest of Europe.

“Historically the ratio has been higher in the UK than in many European countries because we put the policy costs on electricity,” he says.

“Recent price caps indicate that the spread is getting larger. This is one of the problems that the Government said two years ago they would address, by reforming how we allocate green levies and how we tax energy. But so far nothing has happened.”

A dying rollout

The criticism comes after the Government announced it would increase the Boiler Upgrade Grant by 50pc to £7,500 to boost heat pump uptake, a tacit acceptance that the technology is not as popular as hoped.

Before the hike, a total of £150 million a year had been made available to offer £5,000 grants to households that install air source heat pumps and £6,000 grants for those that get ground source ones. But so far only 14,800 vouchers worth about £75 million have been redeemed, with the scheme now in its second year, according to figures published by regulator Ofgem.

The scheme, launched in May last year, has been branded an embarrassment by critics, with the vast majority of its budget going unspent. 

Another idea being floated is to remove the current requirement for some properties to install insulation before a heat pump is fitted.

Mr Foster called the idea “ludicrous” and “a backward step”, adding: “Even advocates of heat pumps admit they need to be used in conjunction with insulation to be effective. 

“It will lead to higher annual bills each and every year. The whole consultation seems to be an attempt to breathe life into a dying scheme.

“Whitehall officials and ministers bought the idea that heat pumps would be as cheap as boilers to install; they were warned by the industry this would not be the case. 

“Now they are panicking as the British public have sent them a very clear message: heat pumps currently cost too much to buy and run compared to a boiler.”

Pricey option

The question puzzling the politicians pushing heat pumps on the public is why the technology remains so much less popular in the UK than the rest of Europe.

The UK installed just 55,000 heat pumps in 2022, far short of the Government’s target of 600,000 a year by 2028. France, by comparison, installed 621,000 last year.

In 2021, the devices made up just 2pc of all heating systems sold in the UK – the lowest share in Europe, according to the European Heat Pump Association.

Twenty other European countries also had higher installation rates than the UK. The highest ratio of heat pumps per household is in Norway (60pc), Sweden (43pc) and Finland (42pc).

The single biggest drawback putting consumers off is cost. The price of installing a new oil or gas boiler is around £4,000, according to the Energy Saving Trust, two to three times cheaper than a heat pump.

And while the Government’s relatively generous grants of up to £7,500 can make a big dent in this figure, installing a heat pump can also require an unknown number of costly electrical upgrades.

A government trial found that 81pc of homes fitting a heat pump needed a new cylinder and 93pc needed new radiators. If heat pumps were guaranteed to save you money once installed, persuading homeowners to sign up would be a lot easier.

But the technology is often more expensive to run than the “non-green” alternative, according to the Government’s own advisers.

The running cost of heat pumps is 10pc higher than that of an average gas boiler – equal to £100 more a year, according to a report by the Climate Change Committee, an independent adviser on tackling climate change. The study was from July 2022, when gas prices were at a record high.

Effective insulation is crucial for heat pumps to function optimally because the devices operate at lower temperatures than gas boilers. Yet around 25 million homes in Britain do not have sufficient insulation. As efficiency drops, the cost of running a heat pump relative to a gas boiler rises.

A heating professional who lives in a rural, mostly off-grid area in England and looks after predominantly oil central heating systems, says heat pumps are unsuited to many properties.

The engineer, who wished to remain anonymous, says: “I would like to dispel the biggest myth around heat pumps that some companies will tell you about money savings.

“Heat pumps are more expensive to run than oil heating and in some cases LPG [liquefied petroleum gas], depending on the property insulation levels and air leakage. In fact, oil heating remains the most cost-effective heating source available.

“The majority of rural and urban properties are not ready for heat pump installation until windows and insulation has been upgraded to its maximum level. Only at this point should you consider installing a heat pump.”

Mr Foster says heat pumps are a “great technology” in the right circumstances, adding: “If I was building a new thermally efficient property from scratch, I’d design it with a heat pump in mind.

“But during the 20th century some European countries were ravaged by war and had to be rebuilt, whereas the UK’s housing stock is relatively old.

“There are an awful lot of buildings built before 1919 that have solid wall construction, typical Victorian terraced houses.

“When you have external walls like that they leak heat, and they’re not ideal for heat pumps.”

Six years ago, Professor Gareth Rees and his wife moved into an 18th-century property in rural Suffolk. The previous owners had installed a ground-source heat pump which worked “temperamentally”. After its 10th birthday, the pump failed completely.

“The verdict was that the pump would have cost between £4,000 and £7,000 to repair,” says Prof Rees. “And that we would have to wait several months – without a hot-water supply – before work could be undertaken.

“Instead, we asked an engineer to bypass the heat pump and install a new, bigger condensing oil boiler in place of the old one. This got us up and running again in only six weeks.”

Prof Rees, a physicist focusing on the Arctic climate, crunched the relative efficiencies of the heating systems himself.

“The oil boiler reduced our heating energy costs by about 36pc, and our carbon footprint – a result of the higher efficiency of the new condensing boiler compared with the old model.

“The heat pump’s coefficient of performance had been considerably less than that often quoted.”

Lord Callanan, the minister for energy efficiency and green finance, insists that heat pumps will grow in popularity as prices fall.

“They are expensive at the moment, which is why we have the upgrade scheme to cushion the impact for people,” he says.

“Prices are coming down as more installers become familiar with them, as the market gets bigger, as advances in technology proceed, prices will fall.

But he admits that there’s still “a long way to go” to make heat pumps a viable option across the country and that they “won’t be appropriate for every home”.

The government-funded Electrification of Heat Demonstration project found that around 90pc of UK households would be “technically capable” of having a heat pump installed.

However, the number of these households for which heat pumps would be cheaper to run than a gas boiler is unknown.

Lord Callanan says: “Traditionally lots of green levies have been placed on electricity, which has made electricity proportionally more expensive than gas. So even though heat pumps are much more efficient, the cost at the moment is probably broadly equivalent.

“So we need to demonstrate that it will be cheaper if you take a gas boiler out and put a heat pump in. And that will unfold over a number of years.”

Faff factor

Cost is not the only drawback putting households off heat pumps. The faff and inconvenience of installing and maintaining a fridge-like white box also plays a part.

Small flats often lack the space needed for the devices, as large hot water cylinders are required, while experts have warned that millions of owners of terraced houses could face having to apply for planning permission to install a heat pump if the unit is placed near their property boundary.

On top of this, the Government launched a review of heat pumps earlier this year over fears they might be too noisy. Air-source heat pumps tend to emit a constant hum of between 40 and 60 decibels, about the same as a fridge or dishwasher.

Even though individually that is below the level usually considered annoying, there are fears that the cumulative impact of multiple heat pumps in residential areas could tip over into disturbance.

A spokesman from the Department for Energy Security and Net Zero said: “Heat pumps are a proven means of decarbonising how homes and businesses are heated, replacing gas boilers which are less efficient.

“They are located outside the home and typically have sound levels similar to a fridge. Issues with noise emissions are very rare and technological advances mean heat pump models have become quieter over time.

“We commissioned an independent review of noise emissions and the outcome of this will inform whether existing permitted development rights are fit for purpose.”

Sensitivity to weather conditions has also caused problems for heat pump owners.

Derek Oxbrough, a former research and development director at an induction heating company, says the air-source heat pump he installed last year at his home in Barkham, Berkshire has been “a complete disaster”.

A shoddy initial installation caused issues with the pump. A missing component was eventually installed, but the system “never worked properly”.

“When the outside temperature was below +3°C the heat pump could not maintain a set point temperature of 19.5°C in our lounge,” he says. “This situation worsened at lower outside temperatures.”

To prevent a heat pump from freezing, it circulates the internal radiator water back into itself to remove any ice build-up. In Mr Oxbrough’s case, this process led to a loss of efficiency.

“The heat pump was nearly as economical as the gas boiler under mild winter temperatures, but its efficiency drastically fell when the defrost cycle started, to the point where at an outside temperature of -6C the heat pump was 60pc more expensive to run.

“I had electricity consumption of £50+ per day in the two-week cold spell prior to Christmas last year due to using a heat pump.”

“There was also a noise and vibration issue when the heat pump was at full power.

“I feel most people are being deceived by this heat pump roll-out and this will result in an expensive problem for them as it has done for me.”

Choice is key

Mr Foster believes the aversion to heat pumps in Britain runs deep.

“The UK fortuitously had an abundance of gas off its coast in the North Sea, so we developed an energy network based on gas,” he says.

“85pc of our homes are connected to the gas grid and use gas heating. Other parts of Europe did not have that advantage so had to find alternative ways of heating their homes.

“A simpler solution to the green energy conundrum would be to just change the gas you use, and use the existing gas infrastructure rather than ripping out all your appliances and changing your lifestyle.”

Hydrogen gas is often posited as a potential alternative. But former energy security secretary Grant Shapps poured cold water on the idea of pumping hydrogen into millions of British homes, pointing to the high cost and impracticalities of converting existing pipework.

Greg Jackson, chief executive of Octopus Energy, which has invested millions into developing cheaper heat pumps, compared switching to hydrogen gas to “flushing champagne down the toilet”.

Ministers have abandoned a planned hydrogen trial in Whitby following a backlash from residents. Another trial, in Redcar, may still go ahead but has not yet been confirmed.

Yet energy leaders believe that consumer choice is key. Ms Williams, of Wales and West Utilities, says: “Heat pumps are absolutely right for a number of homes, and they’re going to be an important part of the heating mix in the future.

“But having that choice for consumers so they don’t just have one costly option is going to be really important, not least for those lower income households.”

Henrik Hansen, managing director at Vaillant, UK and Ireland, a leading heating systems manufacturer, believes a mix of technological solutions is needed for the UK to reach net zero.

“There are homes in the UK less likely to be using heat pumps in the short term,” he says. “On the flipside, there are probably more homes in the UK that could benefit from a heat pump who currently believe they won’t benefit.

“There are many examples of where heat pumps have been a good solution, but there are also other examples when other types of energy would be a better solution.”