Heat pumps are engineering marvels. While not a renewable energy source in their own right – they do not convert solar or wind power to usable energy – heat pumps are ideal companions to renewables. They allow electricity to be used efficiently to generate heat.
Most heating systems we’re familiar with involve burning fuels in boilers, ranges and open fires, but heat pumps work by using electricity to move heat from one place to another. The fan unit draws in the air, extracts the heat from it by passing it through a refrigerant and compressor unit and delivering three to four free units of heat for every unit of electricity used.
Ireland was still in the middle of rural electrification in 1938 when the city of Zurich was installing a heat pump to heat the building to replace wood stoves. The same device heated the building for 63 years until 2001, when it was replaced by a new, more efficient heat pump.
Almost any industrial activity that requires heat up to about 200 degrees can be supplied by a heat pump, and they are already being used in many industries across Europe. Perhaps the most impressive industrial application is in Stockholm, Sweden, which boasts the world’s largest heat pump plant in the world.
The Hammarbyverket plant extracts district heating and cooling from purified wastewater using seven heat pumps with a total power of 225MW, which is enough to heat 95,000 two-room apartments during a normal cold winter.
What is really impressive is how the Hammarbyverket system links up with the city’s district heating network, which also utilises waste heat from data centres and a municipal waste incinerator in its district heating scheme.
Most of the misinformation about heat pumps seems to originate from the oil and gas heating lobby
Sweden leads the way in thinking about heat as both an energy source that must not be wasted, and a vital energy need in a cold climate. Sweden, Finland and Norway have the highest heat pump sales per 1,000 households on the Continent as well as the coldest climates in Europe. In all three countries, there are now more than 40 heat pumps per 100 households, more than in any other country in the world.
But Ireland is not too far behind, with 17 heat pumps sold per 1,000 households in 2024, according to data from the European Heat Pump Association (EHPA) – making ours the fifth biggest market in Europe that year.
Dublin has one district heating scheme in Tallaght that supplies waste heat from an Amazon data centre to local authority buildings and the TU Dublin Tallaght campus. An average data centre produces heat equivalent to its power consumption, meaning that hundreds of megawatts of heat from Ireland’s other 82 or so data centres is wasted annually as it is simply vented, rather than being diverted into district heating schemes or other uses. This is a staggering waste of energy.
We might only be catching up in Ireland at moving heat from where it is generated to where it is needed. But we do generate a good deal of hot air. The Government has set bold targets for heat pumps and the Dáil declared a climate emergency.
But the Oireachtas committee overseeing climate targets plans to set aside more time to hear from the fossil fuel lobby in the lead up to COP30 than climate experts or civil society. With anticipated fines of up to €26 billion by 2030 for failing to meet climate targets, you’d think that the Government would be racing to ban fossil fuel advertising and doubling down on supports for heat pump.
Despite their superior efficiencies, heat pumps are still the subject of misinformation about their suitability for the Irish climate. Consumers are regularly bombarded with advertisements for replacement boilers and HVO leading to confusion.
Most of the misinformation about heat pumps, such as that they don’t work in cold climates or that they are too expensive to run, seems to originate from the oil and gas heating lobby. DeSmog revealed in July 2023 that a barrage of negative press about heat pumps had been funded by a gas lobby group, and in the UK in particular, the anti-net zero campaigns that receive regular coverage in some media.
Some of the challenges to heat pump take-up are very real however. The EHPA website notes that high upfront costs of installation, along with renovation costs and rising electricity prices, are still the biggest barriers to heat pumps across Europe.
The EHPA recommends that governments and regulators should ensure that electricity is no more than double the price of gas, and that electricity costs are reduced by shifting taxes and levies away from electricity bills and phasing out fossil fuel subsidies altogether.
But first we need to let go of the idea that heat pumps aren’t suitable for older buildings. In the UK, St Stephens Anglican church in Lympne, Kent, is heated by a ground source heat pump. If an 11th century church can rely on a heat pump, there really is no excuse.
Sadhbh O’Neill is an environmental and climate policy researcher
