Meet the biggest heat pumps in the world

 

MVV Energie is building the world's most powerful heat pump systems

From the BBC

The pipe that will supply the heat pump, drawing water from the River Rhine in Germany, is so big that you could walk through it, fully upright, I'm told.

"We plan to take 10,000 litres per second," says Felix Hack, project manager at MVV Environment, an energy company, as he describes the 2m diameter pipes that will suck up river water in Mannheim, and then return it once heat from the water has been harvested.

In October, parent firm MVV Energie announced its plan to build what could be the most powerful heat pump modules ever. Two units, each with a capacity of 82.5 megawatts.

That's enough to supply around 40,000 homes, in total, via a district heating system. MVV Energie aims to build the system on the site of a coal power plant that is converting to cleaner technologies.

The scale of the heat pumps was determined partly by limits on the size of machinery that could be transported through the streets of Mannheim, or potentially via barges along the Rhine. "We're not sure about that yet," says Mr Hack. "It might come via the river."

One person well aware of the project is Alexandre de Rougemont, at Everllence (formerly MAN Energy Solutions), another German company that also makes extremely large heat pumps. "It is a competition, yeah," he says. "We're open about it."

Heat pumps soak up heat from the air, ground or, in these cases, bodies of water. Refrigerants inside the heat pumps evaporate when they are warmed even slightly.

By compressing the refrigerant, you boost that heat further. This same process occurs in heat pumps designed to supply single homes, it just happens on a much larger scale in giant heat pumps that serve entire city districts.

As towns and cities around the world seek to decarbonise, many are deciding to purchase large heat pumps, which can attach to district heating networks.

These networks allow hot water or steam to reach multiple buildings, all connected up with many kilometres of pipe. Ever bigger models of heat pump are emerging to meet demand.

"There was a lot of pressure on us to change the heat generation to new sources, especially renewable sources," explains Mr Hack as he discusses the decommissioning of coal-fired units at the Mannheim plant. The site is right by the Rhine, already has a hefty electricity grid connection, and is plugged in to the district heating network, so it makes sense to install the heat pumps here, he says.

He notes that the technology is possible partly thanks to the availability of very large compressors in the oil and gas industry – where they are used to compress fossil fuels for storage or transportation, for example.

Work on the Mannheim project is due to start next year. The heat pumps – with a combined capacity of 162MW – are set to become fully operational in the winter of 2028-29. Mr Hack adds that a multi-step filter system will prevent the heat pumps sucking up fish from the river, and that modelling suggests the system will affect the average temperature of the river by less than 0.1C.

Installations such as this are not cheap. The Mannheim heat pump setup will cost €200m ($235m; £176m). Mr de Rougemont at Everllence says that, at his company, heat-pump equipment costs roughly €500,000 per megawatt of installed capacity – this does not include the additional cost of buildings, associated infrastructure and so on.

Everllence is currently working on a project in Aalborg, Denmark that will be even more powerful than the system in Mannheim, with a total capacity of 176MW. It will use smaller modules, however – four 44MW units – and is due to become operational in 2027, when it will supply nearly one third of all heating demand in the town.

Those 44MW machines are actually the same ones used in a previous project, now fully operational, to the south of Aalborg in Esbjerg. There, they don't run at maximum capacity but rather supply 35MW each.

Large hot water storage tanks, each able to hold 200,000 cubic metres of liquid, will give the system added flexibility, adds Mr de Rougemont: "When the electricity price is high, you stop your heat pump and only provide heat from the storage."

Veronika Wilk at the Austrian Institute of Technology says, "Heat pumps and district heating systems are a great fit." Such systems can harvest heat from bodies of water or even wastewater from sewage treatment plants.

Dr Wilk notes that, when you use multiple large heat pumps on a district heating network, you gain flexibility and efficiency. You could run two out of four heat pumps in the autumn, say, when less heat is required than during the depths of winter.

All the systems mentioned so far harvest energy from water sources but, less commonly, very large heat pumps can use the air as a heat source, too. Even in a relatively cold city such as Helsinki.

"The sea in front of Helsinki is too shallow," explains Timo Aaltonen, senior vice president of heating and cooling at Helen Oy, an energy firm. "We calculated that we would need to build a tunnel more than 20km long to the ocean, to get enough water [with a] temperature high enough."

Helsinki is in the process of radically overhauling its district heating system. The city has added heat pumps, biomass burners and electric boilers to a 1,400km network that links up nearly 90% of buildings in the Finnish capital, adds Mr Aaltonen.

Heat pumps convert single kilowatt hours of electricity into multiple kilowatt hours of heat but electric boilers can't do this and are therefore considered less efficient.

I ask why Helen Oy decided to install hundreds of megawatts of these boilers and Mr Aaltonen says that they are cheaper to install than heat pumps and having them also means he and colleagues don't have to rely entirely on the air, which is limited in terms of how much heat it can provide at scale. Plus, the electric boilers can help to soak up surplus renewables and provide an electricity grid-balancing function, he says.

Heat pumps are booming in cold countries

From Euronews Green

Heat pumps are now the most common method of warming homes in some European countries. In others, the technology is still met with scepticism.

The disparity in heat pump uptake around Europe depends on multiple factors including the subsidies on offer, electricity prices and policies in place to encourage people to install them.

Euronews Green talked to two experts about why some countries have a higher uptake of heat pump technology than others and why policymaking is key to the green energy transition.

Plenty of myth-busting about heat pumps and their ability to function in the cold or in old buildings has improved peoples’ general understanding of how versatile this technology is.

“It is a common perception that heat pumps can only be installed in modern, well-insulated, renovated detached houses,” says Sarah Azau, Head of Communications at the European Heat Pumps Association (EHPA).

“This is however not the case: we have countless examples of heat pumps working successfully in multi-family homes, ancient listed buildings and even in the Arctic permafrost.”

Jan Rosewood is the Director of European Programmes at the Regulatory Assistance Project (RAP), a clean energy non-profit organisation.

He adds that “a key factor in determining whether or not heat pumps get adopted is not so much to do with the building types and the architecture but the economics of using them”.

In those countries where electricity prices are several times higher than gas and heating oil prices, few people have switched to heat pumps. 

This includes the UK for example, which has around 412 heat pumps per 100,000 people compared to a European average of 3,068 heat pumps per 100,000 people, according to Air Source Heat Pumps London.

Where electricity prices are at the most twice as high as gas and heating oil prices we see significant heat pump uptake, explains Rosenow. This is the case in Norway, Sweden, Finland and Estonia for example.

“In terms of the running costs, the electricity price must be no more than twice the price of gas,” Azau adds.

“Heat pumps are very energy efficient - about three to five times as efficient as gas boilers - but they do need a small amount of electricity.”

Different European countries offer financial incentives for heat pumps that include low-interest loans, grant programs and tax rebates.

These are key drivers in the uptake of the technology considering upfront expenses are, on average, two to four times higher than they would be for a gas boiler - usually around €11,500.

Azau adds that support schemes that have changed too quickly or unexpectedly are one of the reasons that heat pump sales have dipped recently - by as much as 47 per cent between the first half of 2023 and the first half of 2024.

“It is essential that a clear direction of travel is set by the EU and national governments through lasting, stable policies,” says Azau.

“This reassures both heat pump manufacturers and consumers. We look forward to seeing this in the planned measures from the new EU Commission, such as the electrification action plan and industrial decarbonisation accelerator act.”

Germany has some of the most generous subsidies for heat pump installation. Landowners can get a grant of up to €18,000 if they buy a ground source heat pump and up to €15,000 for an air source heat pump for an existing property.

France follows close behind with homeowners eligible for grants of up to €15,000 if they buy a ground source heat pump and up to €9,000 for an air source heat pump for an existing property.

In October 2023, the British government increased heat pump grants by 50 per cent, from £5,000 (€5,795) to £7,500 (€8,692).

The full list of grants available in European countries is listed here.

While heat pumps are now the default heating technology in many Nordic countries, in less mature markets they have been met with a degree of scepticism by consumers, Rosenow explains.

He says this is often fuelled by misinformation from the incumbent fossil fuel heating industry.

“In Germany, the heating law resulted in a very polarised debate about heat pumps last year with consumers being uncertain which way to go,” he says.

“Policymakers have a responsibility to provide people with robust and independent information on heat pumps.”

To increase heat pump uptake, Rosenow says that an effective policy mix is the main prerequisite.

This includes “getting energy prices right so that the running costs of heat pumps are lower than fossil fuel alternatives, providing financial support to deal with the upfront cost, regulation to prevent new fossil fuel heating systems from being installed in new and also increasingly existing buildings and good coordination and communication,” Rosewood says.

Emissions from heating and cooling account for ~13% of total global CO2 emissions.  This is the third-largest source of emissions, excluding agriculture and forest clearing. (The largest source is electricity generation, the second largest is land transport)

Denmark introduces a carbon tax on agriculture

Source : Vegconomist

 From Vegconomist

Denmark looks set to introduce what is claimed to be the world’s first carbon tax on agriculture, following negotiations between the government, farmer organisations, trade unions, industry, and environmental NGOs.

The agreement is expected to be formally approved by the Danish parliament in August, and will see a tax of DKK 300 per tonne CO2e introduced on livestock emissions from 2030. This will rise to DKK 750 per tonne CO2e in 2035, but with a basic deduction of 60%; this means that the effective tax will be DKK 120 (€16) per tonne in 2030 and DKK 300 (€40) per tonne in 2035.

“We are investing in the future of our agricultural sector”

The proceeds raised by the tax in 2030-31 will be returned to the industry as a support fund to aid the green transition. The tax is expected to reduce emissions by 1.8 million tonnes of CO2e by 2030, enabling Denmark to achieve its legally binding target of cutting emissions by 70%.

Additionally, 250,000 new hectares of forest will be established in the coming years, and targets have been set to protect at least 20% of nature. Fees for slaughterhouses will be raised by DKK 45 million (€6 million) annually from 2029, and funding will be allocated to upskill labour.

The agreement has been reached despite Europe-wide backlash from farmers against proposed EU environmental policies, which led to some targets being dropped earlier this year. New Zealand has also recently scrapped plans for a tax aimed at tackling livestock emissions.

With the new tax, Denmark continues on its trajectory of progressive agricultural policies. In 2021, the country allocated 580 million DKK to farmers who produce plant-based foods; this was said to be the first time in history that plant foods had been given priority in an agricultural agreement.

In October 2023, Denmark became the first country worldwide to publish a national action plan for plant-based foods. The plan aims to strengthen and promote the country’s plant-based sector as part of the shift toward climate-friendly diets. Its publication came just a few months after a report found that Denmark’s financial sector currently lacks the objectives, knowledge, and ambition to invest in sustainable foods.

In March of last year, the Danish Climate Council recommended that two-thirds of the meat consumed by Danes should be replaced by plant-based foods, and suggested that high-emission foods such as beef should be taxed.

Beef and mutton produce the most methane in agriculture, and methane is 80 times as potent a greenhouse gas over 10 years as CO2 (it takes 12 years for methane to decay into CO2).  Also, expanding beef production means more land clearing, though obviously not in Denmark.  Globally, these two factors make agriculture a major source of greenhouse gases.  In 2024, 88% of Denmark's electricity came from renewables.   And 56% of Denmark's car sales are EVs/PHEVs.   Agriculture is the logical next step to cut emissions.  Heat pumps are another.  Compared to the rest of Scandinavia and Europe, Denmark has fewer heat pumps installed per 100,000 people, partly because its heat pump subsidies are smaller.  Heat pumps are far more efficient for heating in terms of energy use than old-fashioned gas or oil boilers.

Earth is trapping twice as much heat

Earth is trapping much more heat than climate models forecast – and the rate has doubled in 20 years

Ice and reflective clouds reflect heat back to space. As the Earth heats up, most trapped heat goes into the oceans but some melts ice and heats the land and air. Pictured: Icebergs from the Jacobshavn glacier in Greenland, the largest outside Antarctica. Ashley Cooper/Getty

From The Conversation

How do you measure climate change? One way is by recording temperatures in different places over a long period of time. While this works well, natural variation can make it harder to see longer-term trends.

But another approach can give us a very clear sense of what’s going on: track how much heat enters Earth’s atmosphere and how much heat leaves. This is Earth’s energy budget, and it’s now well and truly out of balance.

Our recent research found this imbalance has more than doubled over the last 20 years. Other researchers have come to the same conclusions. This imbalance is now substantially more than climate models have suggested.

In the mid-2000s, the energy imbalance was about 0.6 watts per square metre (W/m2) on average. In recent years, the average was about 1.3 W/m2. This means the rate at which energy is accumulating near the planet’s surface has doubled.

These findings suggest climate change might well accelerate in the coming years. Worse still, this worrying imbalance is emerging even as funding uncertainty in the United States threatens our ability to track the flows of heat.

Earth’s energy budget functions a bit like your bank account, where money comes in and money goes out. If you reduce your spending, you’ll build up cash in your account. Here, energy is the currency.

Life on Earth depends on a balance between heat coming in from the Sun and heat leaving. This balance is tipping to one side.

Solar energy hits Earth and warms it. The atmosphere’s heat-trapping greenhouse gases keep some of this energy.

But the burning of coal, oil and gas has now added more than two trillion tonnes of carbon dioxide and other greenhouse gases to the atmosphere. These trap more and more heat, preventing it from leaving.

Some of this extra heat is warming the land or melting sea ice, glaciers and ice sheets. But this is a tiny fraction. Fully 90% has gone into the oceans due to their huge heat capacity.

Earth naturally sheds heat in several ways. One way is by reflecting incoming heat off of clouds, snow and ice and back out to space. Infrared radiation is also emitted back to space.

From the beginning of human civilisation up until just a century ago, the average surface temperature was about 14°C. The accumulating energy imbalance has now pushed average temperatures 1.3-1.5°C higher.

Scientists keep track of the energy budget in two ways.

First, we can directly measure the heat coming from the Sun and going back out to space, using the sensitive radiometers on monitoring satellites. This dataset and its predecessors date back to the late 1980s.

Second, we can accurately track the build-up of heat in the oceans and atmosphere by taking temperature readings. Thousands of robotic floats have monitored temperatures in the world’s oceans since the 1990s.

Both methods show the energy imbalance has grown rapidly.

The doubling of the energy imbalance has come as a shock, because the sophisticated climate models we use largely didn’t predict such a large and rapid change.

Typically, the models forecast less than half of the change we’re seeing in the real world.

We don’t yet have a full explanation. But new research suggests changes in clouds is a big factor.

Clouds have a cooling effect overall. But the area covered by highly reflective white clouds has shrunk, while the area of jumbled, less reflective clouds has grown.

It isn’t clear why the clouds are changing. One possible factor could be the consequences of successful efforts to reduce sulfur in shipping fuel from 2020, as burning the dirtier fuel may have had a brightening effect on clouds. However, the accelerating energy budget imbalance began before this change.

Natural fluctuations in the climate system such as the Pacific Decadal Oscillation might also be playing a role. Finally – and most worryingly – the cloud changes might be part of a trend caused by global warming itself, that is, a positive feedback on climate change.

These findings suggest recent extremely hot years are not one-offs but may reflect a strengthening of warming over the coming decade or longer.

This will mean a higher chance of more intense climate impacts from searing heatwaves, droughts and extreme rains on land, and more intense and long lasting marine heatwaves.

This imbalance may lead to worse longer-term consequences. New research shows the only climate models coming close to simulating real world measurements are those with a higher “climate sensitivity”. That means these models predict more severe warming beyond the next few decades in scenarios where emissions are not rapidly reduced.

One could despair.  Yet we're far from helpless.  

We can get to 95% renewables in our grid with solar plus storage plus wind, without compromising the reliability of our grids, and we can do this between latitudes of at least 55 degrees north or south of the equator.   Every country should be moving as rapidly as possible to this goal, and when I say as rapidly as possible, I don't mean that we should get there by 2040 but by 2030.   +-30% of emissions come from electricity generation. 

We can run almost all our land transport using battery-electric vehicles.  (+-20% of emissions)  The problem here is that even when we get to 100% EV sales, it will still take a decade or more for the existing stock of vehicles to be completely switched to EVs.  Governments need to tweak tax policy to accelerate EV sales as well as buybacks of old petrol and diesel cars.

If we also start using heat pumps instead of gas/oil heaters, we could cut emissions by a total of 60% over the next ten years.  It's doable.  If only our politician and CEOs stopped lying to us, and took action instead of greenwashing.

Half of homes will need heat pumps by 2040

This analysis is about the UK, but the logic applies everywhere.  Globally, heating and cooling buildings produces 17.5% of global emissions.   Every government everywhere should be aggressively promoting heat pumps, because even if the electricity grid has a high percentage of fossil fuels, heat pumps are far more efficient than other kinds of heating, and so, will produce fewer emissions.

From The BBC

Four in five cars should be electric and half of homes should have heat pumps within 15 years, say the government's independent climate advisers.

By law the UK must reach "net zero" - no longer adding to the total amount of greenhouse gases in the atmosphere - by 2050.

UK greenhouse gas emissions have more than halved since 1990, largely thanks to less electricity coming from fossil fuels and more from renewables. But the Climate Change Committee (CCC) says that to reach the 2050 target we will also need to change how we drive and heat our homes.

Energy Secretary Ed Miliband said the government would consider the advice and respond in due course.

"We owe it to current generations to seize the opportunities for energy security and lower bills, and we owe it to future generations to tackle the existential climate crisis," he said.

Under UK law, the CCC provides independent advice on how much the UK should emit over five-year periods, known as "carbon budgets", and how it might get there.

Each carbon budget is a stepping stone to net zero by 2050. The latest advice is that by 2040, emissions should be 13% of their 1990 levels, for the UK to stay on track.

The CCC advice is not policy, but the government has historically accepted it. If it does, the target will become legally binding, but government will still decide how to achieve it.

Meeting these long-term goals will mean significant changes in the years ahead. One-third of emissions cuts between now and 2040 need to come from households making low-carbon choices, the CCC says.

This will mainly be through switching from petrol and diesel cars to electric vehicles and from fossil fuel boilers to heat pumps, making use of growing supplies of clean electricity. Smaller contributions will come from other choices, such as eating less meat and dairy.

As the graph below shows, these changes are ambitious. But they are deliverable, argues the CCC, without people having to scrap their existing boiler or car early.

Other emerging technologies, like mobile phones and internet connections, have achieved similar rates of increases previously.

"For electric vehicles, the market is already pretty much at parity with internal combustion engine vehicles, so we think just naturally that will start to be a choice people make," Emma Pinchbeck, chief executive of the CCC, told the BBC's Today programme.

"For heat pumps, we're saying it's different, the costs are still higher than a fossil fuel boiler and the government will need to act to help people get those technologies.

"But the rollout rate that we've looked at is similar to what happened to our neighbours in Ireland but also to much colder countries in Europe."

Emissions cuts will be needed in other areas too, such as farming and flying, two of the hardest sectors to decarbonise.

The CCC no longer directly advises against net airport expansion, which it has previously. But it warns the costs of decarbonising aviation will need to be picked up by airlines, which will probably drive up ticket prices.

It says we will need to eat less meat and dairy too. In the CCC's pathway, sheep and cattle numbers fall by 27% by 2040, and the area covered by woodland rises from 13% to 16%.

Cost of net zero

The costs of tackling climate change have become highly politicised in recent years.

The CCC estimates most of the expense will be borne by the private sector and calculates the savings from moving to more efficient technologies should outweigh costs by the early 2040s.

"We are crystal clear in this analysis, in this carbon budget, for the first time we start to see the economy making savings from this investment, and they make savings over and above what we would do if we stay dependent on fossil fuels," Ms Pinchbeck told BBC News.

This should improve energy security and filter down to lower bills in the long term, the CCC argues, provided the government acts to make electricity cheaper.

It advises removing policy costs – funding for social and environmental schemes – from electricity bills. That would cut them by about 19% based on expected 2025 prices, the CCC says, making it more cost-effective for people to switch to electric vehicles or heat pumps.

These costs could instead sit on gas bills or general taxation.

"Regardless of what you think about climate change, what we are laying out today is a massive industrial revolution," said Ms Pinchbeck.

"It will save the economy money by 2040, it saves people money on their energy bills, it saves people money on their driving costs, but all of that is underpinned by a cheaper electricity price."

See also:  Heat pumps: myths and benefits

Heat pumps: myths and benefits

From East Anglia Bylines

The first heat pump in the UK was installed in Norwich in 1945 by John Sumner, the city electrical engineer for Norwich. Nearly 80 years later the technology has made a resurgence: in 2024 there were a record number of heat pump installations in the UK. Over 60,000 air source heat pumps were installed last year alone. Yet despite this growth, only 1% of UK households currently use heat pumps.

This figure highlights a stark contrast between the UK and other European nations. The UK lags far behind in heat pump adoption, with just 412 heat pumps per 100,000 people compared to the European average of 3,068. This is largely due to our access in recent years to cheap coal, oil and gas.

The government’s ambitious target of 600,000 annual installations by 2028 remains a distant goal, hindered by high costs, limited awareness of how heat pumps work, and persistent myths about the technology putting people off making the switch.

A knowledge gap

While nearly half of UK homeowners express interest in low-carbon heating solutions, 73% admit they don’t feel informed enough to make the switch to heat pumps. To combat the knowledge gap, the government has invested £100,000 in a ‘nudge unit‘ to dispel myths and encourage adoption.

Heat pumps are still a relatively unfamiliar technology to many, leading to confusion about their various types and how they work. The three main categories—ground source, air source and water source – often leave people uncertain about which is most suitable for their homes.

Ground source heat pumps extract heat from the ground via buried pipes. This is the most expensive and is only cost-effective for large industrial buildings and apartment blocks.

Air source heat pumps, which are the most commonly used, capture heat from the outside air – even on cold days. There are two types: the more commonly installed “air to water” systems that provide heat to radiators or underfloor heating, and “air to air” systems circulating warm air directly into rooms via ducting.

Water source heat pumps draw warmth from a nearby water source, such as a lake or river, and are relatively rare.

Each type has its own benefits and drawbacks depending on where it’s being installed, but many people struggle to distinguish between them, particularly as air-to-air and air-to-water systems are sometimes grouped together under the same category. This lack of understanding can create confusion about the best system for individual needs, particularly as more people look to make sustainable choices for heating their homes.

Heat pumps can run at up to 400% efficiency, producing three to four times more energy than they consume. Homeowners can expect to save between £260 and £580 annually on energy bills by replacing an old gas or LPG boiler with a heat pump.

According to research by Confused.com Energy, public interest is evident. Searches for “are heat pumps worth it?” surged by 90% in recent months. However, high installation costs – averaging £10,000 for air source systems and £20,000 for ground source systems – remain a significant barrier. While prices are expected to drop by 20-25% by 2030, financial incentives like the UK government’s £7,500 Boiler Upgrade Scheme, and the Scottish government’s additional offer of a £7,500 interest free loan for residents in Scotland, aim to ease the transition now. Depending on the extent of the upgrade (some homes may need new radiators, or the owner chooses underfloor heating or adds solar and battery storage), in many cases, a simple installation may only take around 4.5 years to break even.

Addressing misinformation

A significant amount of misinformation – particularly online, but also from a certain section of the press – has contributed to scepticism about heat pumps.

Critics frequently claim that heat pumps are noisy. Modern heat pumps operate at noise levels comparable to a fridge, meeting strict UK guidelines that limit noise to 42 decibels at the nearest neighbouring property. In flats, compact air-to-air systems have proven successful options.

A common misconception is that heat pumps are ineffective in colder climates, yet they are widely used in Scandinavia where temperatures plummet far below those in the UK. Proper installation and sizing enable heat pumps to function efficiently even in uninsulated homes, as demonstrated in case studies ranging from stone churches to high-rise flats. Some types of heat pumps can work ‘in reverse’ to provide cooling in the summer.

As for insulation, while better-insulated homes allow heat pumps to work more efficiently, they are not a prerequisite. Properly designed systems can heat even uninsulated buildings to comfortable temperatures. Experts recommend improving insulation to maximise energy savings, with measures like loft insulation, double glazing, and adding draft excluders around windows and doors to reduce heat loss and improve overall system efficiency.

A recent survey by energy supplier Good Energy revealed that 15% of respondents mistakenly believed heat pumps require underfloor heating. In reality, heat pumps work effectively with radiators, although underfloor heating can enhance their efficiency due to its lower flow temperature. While some radiators may need upgrading, recent trends in radiator oversizing for safety margins mean existing ones may still suffice, depending on the property.

Economic and environmental benefits

The financial benefits of heat pumps are compelling. Homeowners can save between £260 and £580 annually on energy bills by replacing old gas or LPG boilers with heat pumps. Over time, these savings offset the upfront costs. Homeowners typically break even in 4.5 years. Beyond the financial appeal, heat pumps significantly reduce a home’s carbon footprint, cutting emissions by up to 90%. With home heating responsible for 18% of the UK’s emissions, widespread adoption could make a substantial contribution to achieving net-zero targets. There’s also evidence that installing a heat pump can increase property value by up to 3%. This boost in resale potential reflects growing demand for sustainable homes.

A flexible transition

The government’s push towards heat pumps is sometimes portrayed as coercive by naysayers, but there is no immediate mandate requiring homeowners to switch. Instead, policymakers aim to encourage adoption through incentives and education. Under the government’s Future Homes Standard proposal, gas boilers will be banned for new builds by 2027. While their policy is driving a shift towards low-carbon heating, homeowners in existing properties are free to transition at their own pace.

A proven technology

Heat pumps are not a new or untested technology – the concept behind them dates back to 1756 and was later used in refrigeration. Today, across the globe, nearly 200 million heat pumps are in operation, with proven success in diverse climates. Scandinavia’s widespread adoption demonstrates their reliability in extreme cold, while countries like Germany and France have shown how policy incentives can drive rapid adoption.

As the UK grapples with the twin challenges of high emissions and some of the highest energy costs in the world, heat pumps offer a viable solution. From their efficiency and long lifespan to their potential for cutting bills and boosting property values, the case for heat pumps is strong. But if the government wants to meet its target and gain widespread adoption, their ‘nudge unit’ is going to need to work hard addressing common myths, reducing upfront costs and improving public awareness.

The first step towards the use of heat pumps was taken in Norwich in 1945. Nearly 80 years later, it’s time for the UK to take the next.

We have what Australians call a "split reverse-cycle air-conditioner", which an "air-to-air" unit, heating in winter and cooling in summer.     

Even at low temperatures, heat pumps still work

 From Joule/Science Direct

Main text

Heat pumps have emerged as a key tool in the global transition toward clean and reliable energy and have been identified in multiple net-zero scenarios as the most important future heating technology.1 A question frequently raised is how well these devices perform when temperatures drop below freezing, as some commentators and the media have repeatedly suggested that heat pumps cannot deliver useful efficiencies at lower temperatures.

This commentary responds to this question by analyzing field studies with real-world performance data of air-source heat pumps. It finds that well below 0°C, heat pump efficiency is still significantly higher than fossil fuel and electric resistive heating systems at an appliance level. The standard heat pumps investigated in this commentary demonstrate suitable coefficients of performance for providing efficient heating during cold winters where temperatures rarely fall below −10°C, i.e., most of Europe.

In extreme cold climates, such as where the lowest temperatures approach −30°C, performance data have shown that heat pumps can provide heat at efficiencies up to double that of resistive heating; however, more analysis is required. Even though heat pump efficiency declines during the extreme cold and back-up heating may be required, air-source heat pumps can still provide significant energy system efficiency benefits on an instantaneous and annual basis compared with alternatives.

Background

Air-source heat pumps typically use electricity to drive a refrigeration cycle that moves heat from a colder source to a warmer destination. One important aspect of measuring a heat pump’s performance is its efficiency. Other technical attributes relevant to performance, such as heating capacity, are not covered in this commentary.

Heat pump efficiency is measured by the device’s coefficient of performance (COP), the ratio of the useful heat outputted to energy consumed. Typical COP values for heat pumps lie in the range of 3–6, indicating that 3 to 6 units of heat are created from each unit of electricity used. A year-round average COP of 3–4 is common for household applications.

The temperature difference between a heat pump’s source (the outside air) and sink (heating supply location) plays a determining role in the COP and, therefore, its overall performance. If the source temperature dips and the sink temperature is maintained, the COP falls. Around freezing temperatures, air-source heat pumps also can experience a reduction in COP due to the defrosting of external components.

Ground-source heat pumps typically provide a very high level of efficiency, even during cold weather. The reason is that soil temperature does not change significantly between seasons, resulting in a higher—and more constan—COP. In addition, ground-source heat pumps do not need to expend energy on defrosting.

This commentary focuses on the performance of air-source heat pumps in mild European winters with average January temperatures above −10°C. We refer to these heating conditions as “mild cold climates”, whereas those with average temperatures below −10°C in the coldest month are designated “extreme cold climates”.

Penetration of heat pumps in cold climates

Heat pumps have seen increasing deployment in many countries. Intriguingly, in Europe their use is most concentrated in countries with colder climates. These countries have installed heat pumps for decades and see the highest heat pump penetration both in terms of existing fleet and new sales, as shown in Figure 1. As of 2021, Norway had just over 60 heat pumps installed per 100 households, followed by Sweden and Finland (around 45 each) and Estonia (35), respectively.1 These countries also experienced the highest per capita sales in Europe during 2022. The data do not provide insights about the achieved efficiency of those heat pumps, but the large share of household installations suggests that heat pumps can effectively provide heating in colder climates.

Many countries in Europe experience relatively mild winters. From 1990 to 2020, mean January temperatures across the European Union, the United Kingdom, and Norway ranged from 9.1°C in Portugal to −9.2°C in Finland. Around 80% of European households are in countries where mean January temperatures do not fall below 0°C and 95% of households are in countries where mean January temperatures are higher than −5°C. Such climate zones are not just restricted to Europe, as the data we have analyzed for this paper highlights.

Heat pump efficiency in mild cold climates 

Our research collected raw performance data from seven different field studies, focusing on heat pump efficiency in mild cold climates. The datasets represent a range of climatic zones, heat pump models, and heat pump configurations from Switzerland (CH), Germany (DE), the United Kingdom (UK), the United States (US1), Canada (CA), China (CN) and an additional lab-testing sample from the United States (US2).2,3,4,5,6,7,8 

These datasets are plotted with the average COP in relation to the average outside temperature (°C) (Figure 2). Each dot represents an observation of average COP for space heating and temperature measurements that are either instantaneous (as in CA, CH, CN, DE, and US2) or daily averages (UK and US1). The number of heat pump systems represented in Figure 2 is around 550, and there are 2,760 total measurements. The heat pumps are a mix of air-to-water (CH, DE, UK) and air-to-air (CA, CN, US1, and US2) systems. More information on the system configurations can be found in the supplemental information.  When the outside temperature was between 5°C and −10°C, the mean COP across all systems was 2.74 and the median was 2.62, sufficient to meet heating loads at much higher efficiency than fossil heating and electric resistance heat alternatives.

 

Heat pump efficiency in extreme cold climates

Field studies also have been conducted in extreme cold climates, which we consider to be below −10°C and approaching −30°C. In these temperature ranges, specially engineered “cold-climate heat pumps” are typically deployed. We analyze their performance results in extreme cold climate conditions. 

Some of the market-leading cold-climate air-source heat pumps were tested in Finland at very low temperatures.9 Models from Mitsubishi and Toshiba both provided COPs above 2 even at temperatures as low as −20°C. At −30°C, COPs were still between 1.5 and 2 for the Mitsubishi model and 1 and 1.5 for the Toshiba model. 

In field testing carried out in Minnesota (US3), the performance of central-ducted cold-climate air-source heat pumps was measured at four different sites.10 Three of the sites returned COPs between 1 and 2 during heat-pump-only operation below −12°C. 

Field testing was also conducted in Alaska by the Oak Ridge National Laboratory (US4) using a cold-climate air-source heat pump.11 These tests found that the COP remained relatively high, achieving 2.0 at −25°C and 1.8 at −35°C.

 In the past, when I have suggested that heat pumps are the way to go for heating, many have commented that heat pumps don't work at very low temperatures.  It seems that this was true for early heat pumps; but the newer ones, which use a different refrigerant (a kind of propane) are much better.  It may be that at the very coldest places (-30 C) , heat pumps won't work, and we'll still have to use more conventional heating.  But everywhere else, it's an option.  Heating buildings creates 10-12% of emissions.  So it's important that we find better ways to do it.

The secret to decarbonising buildings lies under your feet

Crews drill a borehole to install networked geothermal, which heats and cools nearby homes using the ground as a battery. Eversource

From Grist

Along with earthworms, rocks, and the occasional skeleton, there’s a massive battery right under your feet. Unlike a flammable lithium ion battery, though, this one is perfectly stable, free to use, and ripe for sustainable exploitation: the Earth itself.

While temperatures aboveground fluctuate throughout the year, the ground stays a stable temperature, meaning it’s humming with geothermal energy that engineers can exploit. “Every building sits on a thermal asset,” said Cameron Best, director of business development at Brightcore Energy in New York, which deploys geothermal systems. “I really don’t think there’s any more efficient or better way to heat and cool our homes.”

At the start of June, Eversource Energy commissioned the United States’ first networked geothermal neighborhood operated by a utility, in Framingham, Massachusetts. Pipes run down boreholes 600 to 700 feet [200 metres] deep, where the temperature of the rock is consistently 55 degrees Fahrenheit [13 Celsius]. A mixture of water and propylene glycol (a food additive that works here as an antifreeze) pumps through the piping, absorbing that geothermal energy, then flows to 31 residential and five commercial buildings, where fully electric heat pumps use the liquid to either heat or cool a space. If deployed across the country, these geothermal systems could go a long way in helping decarbonize buildings, which are responsible for about a third of total greenhouse gas emissions in the U.S.

Once a system is in place, buildings can draw heat from water pumped from below their foundations, instead of burning natural gas piped in from afar. Utilities use the same equipment to deploy networked geothermal as they do for gas lines, and even the same kind of pipes — they’re just circulating fluid instead of gas. The networks don’t need special geology to operate, so they can be set up pretty much anywhere. The project in Framingham, then, could be the start of something big.

In Massachusetts, commercial buildings tend to be more cooling-heavy, meaning that they cool more than heat over the course of a year, whereas residential homes tend to be more heating-heavy. Lots of different structures, with different heating and cooling needs, share one loop of piping in a geothermal network. “When you combine them onto the same loop, you keep the ground temperature stable,” said Eric Bosworth, manager of clean technologies at Eversource Energy. “You’re not putting energy in or out of the ground when you add all of the loads up.”

To scale up, a geothermal loop like Framingham’s might connect to an adjacent neighborhood, and that one to another. “In the end, what we would like is if the gas utilities become thermal utilities,” said Audrey Schulman, executive director of the nonprofit climate-solutions incubator HEETlabs (a spinoff of the climate nonprofit HEET, which began pitching the idea to Eversource and other utilities in 2017). “Each individual, shared loop can be interconnected, like Lego blocks, to grow bigger and bigger.”

That goal may not be far off as utilities face increasing regulatory pressure to phase out gas. So Eversource Energy and two dozen other utilities, representing 47 percent of the country’s natural gas customers, have joined into an information-sharing coalition called the Utility Networked Geothermal Collaborative. “We’ve made a point to think about: Are we really a gas company, or are we a thermal energy delivery company?” said Holly Braun, business development and innovation manager at the Oregon utility NW Natural, which co-founded the coalition.

These geothermal systems hinge on the humble heat pump. For most homes, an “air-source” heat pump is currently the best option: Using an outdoor unit, it extracts warmth from even chilly winter air and pumps it inside. It then reverses in the summer to act like an air conditioner.

A heat pump in a geothermal system works the same way, only instead of extracting heat from air, the appliance extracts it from the water that’s been coursing underground. In the summer, the heat pump cools a space by injecting indoor heat into the water, which is then pumped back into the Earth. That helps warm up the ground, recharging the subterranean battery so there’s plenty of energy to extract in the winter.

A networked geothermal system is extremely efficient. It scores a “coefficient of performance,” or COP, of 6, meaning for every one unit of energy going in, you get six units of heat out. By contrast, gas furnaces have a COP of less than 1.

These heat pumps are exploiting water moving through rock that’s consistently 55 degrees [F; 13 degrees C]. An air-source heat pump in the same neighborhood might have to run when it’s 10 degrees [F; -12 degrees C] out, meaning it’ll have to work harder to provide the same amount of heat. Accordingly, its COP of 2 or 3 would still far outpace a gas furnace, but not approach geothermal’s COP of 6. “That means you have a higher efficiency with a ground-source system, which, of course, helps then with running costs,” said Jan Rosenow, who studies heat pumps at the Regulatory Assistance Project, a global energy NGO.

That kind of efficiency will be critical if the U.S. is going to wean itself off fossil fuels. The more gas furnaces people replace with electric heat pumps, the more demand on the electrical grid. But the more efficient that engineers can make heating and cooling systems, the less capacity utilities will have to add to the grid. “Ground-source heat pumps, and particularly those community networked shallow geothermal, take the lowest electricity draw on that coldest day in winter,” said Tamsin Lishman, CEO of Kensa Group, which is pioneering networked geothermal in the United Kingdom. “It supports a substantial saving in the upgrade needed in the grid.”

But if a utility has perfectly good infrastructure already in the ground to deliver gas, and it’s making good money doing so, why would it invest in a new kind of geothermal infrastructure? The reality is that a lot of that gas infrastructure isn’t particularly good, and is downright dangerous if it’s leaking an explosive gas. A utility might use networked geothermal to just swap in water for gas. “If you’re in a situation where you’re going to need to upgrade your pipe anyway, or replace it, you maybe think about: Do I replace it instead with a pipe that doesn’t require fuel, and it’s naturally replenishing energy from the ground?” Braun said.

At the same time, utilities are under mounting pressure to phase out natural gas: Last year, New York became the first state to ban it in most new buildings. Utilities are also staring at mandates in states like California, Vermont, and Colorado to slash their overall carbon emissions, and they can’t do that if they keep delivering the same amount of natural gas. “If you’re in a jurisdiction that says ‘no new gas,’ well, you don’t put in new gas,” Braun said. “You’ve got to have something else, or you just keep shrinking your business.”

For new housing developments in particular — especially where recent ordinances have limited the amount of new buildings that can be connected to gas — they can drill the boreholes and lay the piping for buildings, and the homes will be ready to go fully electric. “We could lose those customers — we could just take ourselves out of the game — or we could present them with a new, decarbonized option that utilizes our existing strengths,” said Morgan Hood, manager of innovative products and services at Vermont Gas Systems, which co-founded the Utility Networked Geothermal Collaborative. “That’s what geothermal does.”

Though networked geothermal is vastly more efficient than burning gas in a furnace, it’s still unclear how it would impact a customer’s energy bill. Because utilities are still experimenting with these systems, they haven’t settled on a rate structure. One option may be a flat monthly rate to tap into the geothermal network, depending on how much water a given structure needs to provide adequate heating and cooling. It’s a relatively new technology, so the costs to install are still high: Eversource says its budget for the Framingham project was around $18 million for those 36 residential and commercial buildings. But as with any technology, costs will come down as the technique matures.

If the United States is going to properly decarbonize, the home of tomorrow could ditch natural gas and instead use a heat pump to tap into the air or the earth itself as a natural battery. The energy’s there — it’s always been there — now it’s just a matter of realizing its full potential.

Seems expensive ($500,000 per building!), though, as the article says, costs will fall.  But they'd have to fall a lot to make this competitive.  An air-source heat pump might still end up being a lot cheaper, even though it is less efficient.  However, perhaps they don't need to drill down 700 feet.  Perhaps, going down only 100 feet (30 metres) may still work, even though there would be fluctuations between summer and winter temperatures instead of a steady 13 degrees C deeper down.

Globally, 80% want more climate action

It's tempting to rail against ordinary people when it comes to climate action. To blame mankind as a whole for its stupidity and greed. After all, we know that temperatures are rising, that heatwaves, droughts and floods are becoming much worse and more common.  So why is there not enough action? But ordinary people do want action. It is the politicians, the rich, the owners of oil companies, directors of companies who, while pretending to want action, do their best to stop it.


From Al Jazeera

Four in five people want their countries to ramp up efforts in the fight against climate change, according to a United Nations survey billed as the largest yet on the issue.

The UN Development Programme (UNDP) published the poll on Thursday, finding that a majority of people in 62 of the 77 countries surveyed said they supported a quick transition away from fossil fuels to clean energy.

These included the world’s biggest greenhouse gas emitters, with 80 percent in China and 54 percent in the United States supporting the move, though respondents in Russia were notably less keen, with only 16 percent approving.

“As world leaders decide on the next round of pledges under the Paris Agreement by 2025, these results are undeniable evidence that people everywhere support bold climate action,” said Cassie Flynn, UNDP global climate director.

Conducted in collaboration with Oxford University and GeoPoll, the survey posed 15 questions by randomised telephone calls to 75,000 people in 77 countries, the populations of which represent 87 percent of the world’s total – making it the biggest poll of its kind.

Overall, 80 percent of those polled wanted to see stronger commitments to addressing the problem, the clamour for action rising to 89 percent in poorer countries feeling the brunt of climate change.

Climate anxiety was higher in poorer countries like Fiji, where 80 percent are more worried about the problem compared to a year ago, followed by Afghanistan (78 percent) and Turkey (77 percent). Saudi Arabia saw the lowest increase in climate fears, with 25 percent more concerned.

Overall, the survey found 56 percent of respondents said they think about climate change at least once a week. Over half of those surveyed said they were more worried about climate change than last year, compared with 15 percent who said they were less worried.

Climate change is also changing people’s lives, with 69 percent of respondents saying that global warming had impacted major decisions, such as where to live or work and what to buy.

But Achim Steiner, head of the UNDP, said these concerns do not necessarily translate into electoral and consumer decisions.

He pointed to what he called a “perception gap” when it comes to climate action, summing up people’s typical reaction as: “I would do more. But the others won’t. So I will not do anything."

There are things you can do.  

You could eat less meat, especially beef and mutton, and drink less cow's milk.  The less, the better.

You could buy an EV or a plug-in hybrid (PHEV).  Yes, that can be expensive in the USA, because it’s just placed a penal tariff on imports of Chinese EVs and Chinese EV batteries, which are the cheapest in the world.   But in the rest of the world, EVs are plummetting in price.  As are electric 3-wheelers.   An EV will soon cost the same as a petrol car, outside the USA, anyway.   Make your next car an EV.

You can put solar panels on your roof (if you own your own property.)   If you don't, and can't, buy your electricity from a green supplier.   If we all insist of buying renewables from a green electricity utility, they will be forced to build more solar and wind farms.  Don't buy from a so-called green electricity supplier which claims its green credentials because it buys carbon offsets.  These are (mostly) a furphy, a scam. 

You could switch your heating from gas/oil to electric.  There's been some opposition to heat pumps because they supposedly don't work.  That's piffle; they do.  They cost more up front than gas or oil boilers/heaters, but they're cheaper to run.  Some polities provide subsidies to encourage the switch.

Together, all these steps will cut your personal emissions by 80%.  

And, most important, you can vote.  Don't be distracted by other policy issues.  Vote for the Party which is going to do most to cut emissions.  Even if in other ways they are imperfect.

It's up to us, and most of us want to do something.  You can make a difference.  Start today.

Will hotter heat pumps win converts?

 From The BBC

The first heat pumps Graham Hendra sold, about 15 years ago, weren't very hot.

"To get 50C - that was quite hard," says the former wholesaler, referring to the temperature of the water that these devices sent to radiators, known as the flow temperature.

Today's gas combi boilers are typically designed for flow temperatures of around 50-60C.

The older heat pumps might have struggled to heat some homes adequately unless the homeowner decided to install larger radiators, for example. The increased surface area of such radiators helps transfer heat into the room.

But a new breed of heat pumps is emerging. Engineers have gradually improved the technology, meaning that heat pumps are now able to supply much higher temperatures, sometimes in excess of 70C.

A major change has been the rise of new refrigerants, including R290, or propane. This is the fluid that circulates inside a heat pump. In an air source device, the refrigerant captures warmth from the outside air, even on cold days. By compressing the slightly warmed refrigerant, the heat pump is able to increase the temperature and then transfer that heat into a property.

R290 is more environmentally friendly than older refrigerants so leaks are not as potentially damaging in climate change terms. Plus, it is up to 34% more efficient, which helps heat pumps supply higher temperatures without incurring severe efficiency losses.

Mr Hendra is now technical director at Genous, a firm that gives advice to homeowners on how to make their properties more energy efficient.

"We have a thing in our industry that I call 'temperature anxiety'," he says, likening it to the "range anxiety" that some consumers have about electric cars.

But the advent of hotter heat pumps means that such concerns are increasingly becoming irrelevant, he suggests.

It might take time to convince some, however. Paul Ciniglio, head of whole home retrofit at National Energy Foundation, a charity, is currently working on a project in Bicester covering more than 500 homes.

"We're trying to get as many as a quarter of them to sign up to heat pumps but it's proving really hard going," he says. "There has been so much negative press."

Some residents are sceptical the heat pumps will be hot enough, he explains, adding, "With the advent of this new refrigerant, it could be a game-changer."

Among the firms offering R290-based heat pumps are Octopus Energy, a renewable energy company. It recently announced a heat pump called Cosy 6, which can heat water up to a maximum of 80C. In principle, homeowners could change their heating system over with little fuss, says Alex Schoch, head of flexibility. "Combi boiler out, heat pump in," as he puts it. This could make heat pumps viable in a broader range of UK homes, which are notoriously poorly insulated in comparison with much of Europe.

Vaillant's aroTHERM plus heat pump works in outdoor temperatures as low as -20C and can supply hot water at up to 75C, though to remain efficient it is best not to exceed 55C, according to the manufacturer.

Another company, Vattenfall, makes a heat pump that uses a different refrigerant, R744, or CO2. It can supply even higher temperatures, up to 85C. The company expects to install 300 in Europe this winter, mostly for housing associations.

And a spokesman for Daikin says that its Altherma heat pump, which uses R32 as a refrigerant, can reach 70C. The firm plans to launch a range of R290-based heat pumps in 2024.

Heating contributes about 18% to global greenhouse gas emissions, and heat pumps are much more efficient than old-fashioned gas boilers.  If we replace all the old fossil-fuel boilers and power the heat pumps with green electricity, we could substantially reduce emissions.  C'mon governments:  get your act together!

Source: Our World in Data

Yes, heat pumps do work in winter

From EuroNews Green

Oyvind Solsta’s “light bulb” moment with heat pumps came upon reading that the heat they produce far exceeds the amount of electricity that goes in.

Installing a heat pump in his house in the hills of Oslo has greatly benefited the 56-year-old communications adviser for a railways company: improving his comfort, finances and climate footprint.

Norway is among the countries with the most heat pumps per capita, along with neighbouring Finland and Sweden.

"When I researched this, I read that a heat pump can generate the heat equivalent of three to four times the amount of electricity you put into it," said Solsta.

"So just that fact made a light bulb go off above my head, thinking 'This has to be clever'."

Hundreds of thousands of Norwegians have had the same bright idea, including Crown Prince Haakon who has had heat pumps installed at his official residence.

The International Energy Agency (IEA) considers the technology as instrumental in combatting climate change as electric vehicles, since heating solutions generate some four billion tonnes of carbon dioxide per year, representing eight per cent of global emissions.

The fact that Nordic countries, known for their harsh winters, are among the biggest users disproves the often-held assumption that the technology does not work when the temperature plummets.

The myth has fuelled resistance across continental Europe.

"There are a lot of false myths out there about heat pumps. Some oil and gas producing countries such as Russia, some people, some sectors, some businesses don't want to see this transition," explained Caroline Haglund Stignor, a researcher at RISE Research Institutes of Sweden.

"Yes, heat pumps work in cold climates. Yes, heat pumps work in old buildings."

To heat a home, heat pumps extract outdoor heat - which exists even in cold weather - and inject it indoors.

Early models did not include defrosting systems or variable speed compressors, which nowadays enable them to run more efficiently in a wider range of temperatures.

While their efficiency declines somewhat in cold weather, they are still more efficient and greener than other options, experts say.

"This is a mature technology that works, proven to keep millions of homes warm every winter. But it's a continuous development to make it even better," Stignor said.

According to a study by the independent group Regulatory Assistance Project (RAP), air source cold-climate heat pumps can be up to twice as efficient as electric heating when outdoor temperatures fall to -30 Celsius.

In France, heat pump detractors also argue they lead to higher electricity consumption, don't work well in all conditions, such as poorly insulated homes, and require costly installation.

Oil and gas furnaces remain popular in many countries.

In Germany, coalition partners this year finally reached an agreement to ban fossil-based heating as of 2045.

The state now subsidises heat pumps, which in 2022 were used in just three per cent of homes, and sales are beginning to take off.

Contrary to many European countries, Norway has almost no district heating, and banned oil furnaces in January 2020.

To keep warm during its cold winters, the country relies primarily on its abundant and clean electricity, thanks to its vast hydropower resources.

By producing about three to five kWh of thermal energy for every kWh of electricity consumed, heat pumps are instruments for energy efficiency - a key aspect of the fight against climate change - and also allow consumers to make major savings.

After replacing his electric radiator with an air-to-air heat pump two years ago, Solstad saw his electricity bills shrink.

"In the first four months, our consumption decreased by 20 per cent compared to the previous year even though we bought an electric car in the meantime," he said.

While his initial investment may seem costly, at around €2,500 including installation, he thinks it will pay for itself "in just a few years".

As an added bonus, his heat pump works as an air conditioner in summer.

When electricity prices went through the roof last year during the energy crisis brought on by the war in Ukraine, sales of heat pumps hit a record high in Norway, jumping by 25 per cent.

The trend continued in the first half of this year.

"Norwegians have understood that they can expect higher electricity prices in the coming years compared to the past," explained Rolf Iver Mytting Hagemoen, head of the Norwegian Heat Pump Association (NOVAP).

"And energy efficiency is an increasingly hot issue," he said.

Heat pumps work perfectly in cold weather

It is a common misconception that heat pumps don't work well in very cold conditions. Actually, they are widely used in countries where winter temperatures go way below zero. As this research shows, reported in The Guardian, heat pumps as twice as efficient as fossil-fuel heating in subzero temperatures.

Heat pumps are more than twice as efficient as fossil fuel heating systems in cold temperatures, research shows.

Even at temperatures approaching -30C, heat pumps outperform oil and gas heating systems, according to the research from Oxford University and the Regulatory Assistance Project thinktank.

Heat pump uptake is rising in many countries as fossil fuel energy prices have soared following the invasion of Ukraine and as governments seek to reach net zero greenhouse gas emissions.

But the UK has lagged far behind. France, for instance, installs 10 times as many heat pumps as the UK, where many people are unfamiliar with them and doubts about their efficacy have been widely publicised. Reports have spread that they do not work well in low temperatures despite their increasing use in Scandinavia and other cold climates.

The research, published in the specialist energy research journal Joule, used data from seven field studies in North America, Asia and Europe. It found that at temperatures below zero, heat pumps were between two and three times more efficient than oil and gas heating systems.

The authors said the findings showed that heat pumps were suitable for almost all homes in Europe, including the UK, and should provide policymakers with the impetus to bring in new measures to roll them out as rapidly as possible.

Dr Jan Rosenow, the director of European programmes at the Regulatory Assistance Project and co-author of the report, said: “There has been a campaign spreading false information about heat pumps [including casting doubt on whether they work in cold weather]. People [in the UK] don’t know much about heat pumps, so it’s very easy to scare them by giving them wrong information.”

The Guardian and the investigative journalism organisation DeSmog recently revealed that lobbyists associated with the gas boiler sector had attempted to delay a key government measure to increase the uptake of heat pumps.

The UK government is consulting on proposals for incentives to households to take up heat pumps, which at about £7,000 or more can cost two or three times as much up front as gas boilers. Boiler companies are also to be penalised if they fail to sell enough heat pumps, under a “market-based mechanism” that will require them to sell a certain quota of heat pumps or pay a penalty.

Some proponents of gas boilers have railed against the quota, which they claim will add costs to consumers, and at least one boiler company has responded by telling customers that the price of new gas boilers is likely to go up as a result of this green measure.

The UK is increasingly out of step with a strong international push towards low-carbon heating. Yannick Monschauer, an energy analyst at the International Energy Agency, said: “Worldwide, the share of heat pumps in heating equipment sales is set to more than double by 2030 under today’s policies, as deployment also accelerates in colder climates.”

A heat pump installed in a house in Frankfurt, Germany. The UK is lagging far behind on uptake of the technology. Photograph: Michael Probst/AP