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By Euronews Green
Published on 07/11/2023 – 17:17•Updated 08/11/2023 – 09:22

Heat pumps have been heralded as a major clean energy solution, but slammed for being too costly. Here’s what you need to know.

You’ve probably heard of heat pumps by now – devices that take energy from the air, ground and water and transform it into heat or cool air. But how, when and where do they work exactly?

Given the urgency of the energy transition, it’s understandable that discussions about which renewable solutions are best can get rather… heated. And chances are you’ll have first encountered heat pumps in a positive or negative light before getting to grips with the basics.

More and more people are installing the technology. Last year, heat pumps helped Europe to save 8 million tonnes of CO2 emissions, as 3 million units replaced around 4 billion cubic metres of fossil gas – so there’s definitely big potential.

How do heat pumps work?

Air, water and ground heat pumps work by taking energy from these sources and turning it into heat or cold air. They do this within the ‘refrigerant cycle’ – with its four phases of evaporation, compression, condensation and expansion, the European Heat Pump Association (EPHA) explains.

Essentially, the collected heat is used to turn the refrigerant fluid in the pump’s heat exchanger into gas, which is then concentrated to a high pressure in the compressor, prompting a rise in temperature. Extra energy is needed to run this bit of the machinery – ideally from green electricity, which would make the whole process carbon neutral.

The hot and highly pressurised vapour then passes through the second heat exchanger, known as the condenser. This is where the refrigerant discharges heat into the home’s heating system – be it a water-based system like radiators or underfloor heating, or an air conditioning unit.

Releasing its heat returns the refrigerant to a liquid state, which then passes through a pressure-lowering device (the expansion valve) before beginning the cycle all over again.

Heat pumps can be used in homes, offices and in industrial settings. They have the virtue of being very efficient; for every unit of energy that goes in, you get around three units of heat out.

Do heat pumps work in cold climates?

This is one of the main myths about heat pumps. The reality is that the four countries with the largest share of heat pumps – Norway (60 per cent of households), Sweden (43 per cent), Finland (41 per cent) and Estonia (34 per cent) – face some of the coldest winters in Europe.

A recent study found that heat pumps can be successfully installed in countries where winter temperatures rarely fall below -10C, which covers most of the continent. Even approaching -30C, they can still be more efficient than electric heating.

The reason is that in sub-zero temperatures which have us shivering, outside air and water still contain useful amounts of energy. The key measurement here is the ‘coefficient of performance’ (or COP) which is the heat that can be produced for every unit of energy that goes in.

Most homes will find their heat pumps have a COP of three-to-four on a yearly average. They do get less efficient the colder it gets, but studies show that heat pumps can hold their own remarkably well even in cold snaps.

In Finland for example, lab tests on some market-leading heat pumps showed that two models have COPs above two around -20C. And at -30C, COPs are still above one, so can still provide heat.

Ground-source heat pumps might be better in these climates, according to another study, as soil temperatures do not shift so dramatically between seasons (and the equipment doesn’t need to use energy defrosting).

One EPHA award-winning project in Finland combines geothermal energy with heat pump technology to create a moveable system that powers construction sites. The ‘Geolo’ operation in Vantaa is efficient until -30C, and has been used to help build a high school and housing.

Can you install heat pumps in old and existing buildings?

There are around 20 million heat pumps installed in Europe – avoiding 54 megatonnes of CO2, roughly the annual emissions of Greece.

Many people would like to join the heat pump wave, but are unsure if the devices are the right fit for their homes.

One concern is that they won’t work in old buildings. But EPHA says that heat pumps are suitable for any type of building, provided the existing heating or cooling system is compatible.

A government-funded project in the UK has shown they can be installed in homes from every style and era, from Victorian mid-terraces to pre-WWII semis and 1960s blocks of flats.

“Heat pumps powered by clean, renewable energy will be key to warming UK homes in a net zero future,” said Energy and Clean Growth Minister, Lord Callanan.

“This trial demonstrates that low-carbon heating systems are an effective alternative for homes of all types and ages. As technology continues to improve and costs plummet over the next decade, they will become the obvious, affordable choice for consumers.”

Bath Abbey in England shows that even the grandest old building can make space for a heat pump. But the biggest stumbling block for Brits tends not to be planning permission, but cost.

To date, most heat pumps in the UK have been installed in large, off-gas grid homes by well off early adopters, housing developers or social landlords, according to Energy Systems Catapult.

Do heat pumps cost more to run than gas boilers?

There’s no doubt that heat pumps are currently prohibitively expensive for many people.

An air source heat pump costs around £10,000 (€11,500) to buy and install. Average upfront costs are around two to four times higher than gas boilers.

The price of electricity is also more expensive than the price of gas – around three times unit for unit in the UK. Unfortunately this can eat into the efficiency savings from having a pump, but it depends on the energy prices in your country – as this handy calculator from the International Energy Agency (IEA) illustrates.

And the IEA states that heat pumps can save consumers money in the long run, while shielding them from price shocks. Household savings were up to around €840 in Europe, according to a 2022 report.

“With appropriate support for poorer households to manage the upfront costs, heat pumps can meaningfully address energy poverty” it adds.

This depends on national policy decisions, of course, with a range of subsidy offers across Europe.

Do heat pumps only work in well insulated homes?

There are other associated costs with having a heat pump. Since the hot water they produce comes out at lower temperatures than gas boilers, bigger radiators are a plus.

Double glazing and other insulation-tightening features will also help your home to retain more of the heat, which all come at a cost.

But, according to one expert, “houses do not have to be extensively renovated in order to allow for an installation of a heat pump.”

Writing for the science blog of Fraunhofer Institute for Solar Energy Systems (ISE), Marek Miara adds that, the lower the heat losses, the more efficiently a heat pump can operate. So renovation measures to reduce heating energy demand do make sense, as with any other heating system.

Are heat pumps noisy?

Ground source heat pumps don’t make much noise at all.

Air source heat pumps are generally composed of an outdoor and indoor unit. The latter part generally has sound levels between 18 to 30 decibels – around the volume of someone whispering, according to EHPA.

Most outdoor units have a rating of around 60 decibels, which it compares to normal conversation or moderate rainfall.

“Also remember: in the summer when you’re out in the garden heat pumps usually don’t run as no heating is required,” says Jan Rosenow. The director of the Regulatory Assistance Project (RAP), a clean energy NGO based in the UK, has compiled a helpful thread of false heat pump myths on X, where you can find more fact-checking to assist your energy choices.

By Euronews Green with AFP
Published on 30/10/2023 – 17:00•Updated 31/10/2023 – 08:38

This Norwegian man saw his electricity bills shrink after replacing his radiator with a heat pump.

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.

This Norwegian man saw his electricity bills shrink after replacing his radiator with a heat pump.

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.

Do heat pumps work in cold climates?

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.

Are heat pumps better than electric heating?

“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.

How are heat pumps helping Norwegians save money?

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.

How are heat pumps helping Norwegians save money?

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.

We are proud to announce that we have begun introducing Warmichko heat pumps into the EU market.