Published on: November 19, 2024 / Update from: November 19, 2024 - Author: Konrad Wolfenstein
Quotes from experts on the efficiency of heat pumps – Image: Xpert.Digital
The efficiency of heat pumps: A sustainable alternative to fossil heating systems
Heat pumps have become significantly more important in recent years, especially in the context of the energy transition and climate protection. They are considered one of the most efficient and environmentally friendly technologies for heating buildings. But what makes heat pumps so special and why are they viewed by experts as a future-oriented solution? This article highlights the most important aspects of heat pump efficiency, supplemented by interesting facts and explanations.
1. Efficiency and efficiency
Functionality and efficiency of heat pumps
Heat pumps use energy stored in the environment to heat or cool buildings. They extract heat from the ambient air, the soil or the groundwater and convert it into usable heating energy. The big advantage of this technology is that it delivers many times more heat for every kilowatt hour of electricity used. According to the energy service provider GASAG, heat pumps achieve efficiencies of 250 to 500 percent. This means that they can generate around 2.5 to 5 times as much thermal energy from one kilowatt hour of electricity. In other words: “Heat pumps generate 25 to 50 kilowatt hours of heat from 10 kilowatt hours of electricity,” which makes them significantly more efficient than conventional fossil fuel heating systems.
Comparison to fossil heating
In comparison, modern oil or gas boilers achieve efficiencies of around 80 to 90 percent. These systems burn fossil fuels to produce heat, with some of the energy remaining unused and lost as waste heat. Heat pumps, on the other hand, use free and inexhaustible environmental energy, which significantly increases their efficiency.
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2. Annual performance factor (JAZ)
The annual performance factor (JAZ) as an efficiency indicator
An important indicator of the efficiency of a heat pump is the so-called annual performance factor (JAZ). This indicates how much heat is generated over a year in relation to the electrical energy used. For example, a JAZ of 4 means that only 1 kilowatt hour of electricity is required to provide 4 kilowatt hours of heating heat. The Federal Environment Agency emphasizes: “The higher the annual performance factor of a heat pump, the more energy-efficient, environmentally friendly and cost-effective it works.”
However, the JAZ depends heavily on various factors, such as the type of heat pump (air, water or geothermal heat pump), the outside temperature and the quality of the building insulation. In well-insulated buildings with moderate heating requirements, heat pumps can achieve particularly high JAZ values.
3. Efficiency in cold regions
Use in cold regions: A look at Scandinavia
A frequently expressed criticism of heat pumps is their supposedly low efficiency in cold climates. But Scandinavia in particular impressively shows the opposite: In countries like Sweden and Norway, where winters are often long and harsh, the heat pump has established itself as an extremely effective heating solution. These countries even have the highest heat pump density in Europe. “With the highest heat pump ratio in Europe, Scandinavia shows how effectively this technology can be used even in cold regions.” Thanks to modern technologies such as inverter heat pumps or special refrigerants, these systems can work efficiently even at extremely low temperatures.
In Scandinavia, geothermal heat pumps are also often used because the ground has relatively constant temperatures even in winter. This means that the efficiency of these systems remains high even at temperatures below zero.
4. Environmental friendliness and sustainability
In addition to their high efficiency, heat pumps particularly score points for their environmental friendliness. Since they mainly rely on renewable energy sources - namely air, geothermal or water heat - they make a significant contribution to reducing CO₂ emissions. In contrast to fossil heating systems, their operation does not produce any direct emissions. This makes them an important technology in the fight against climate change.
Another advantage is their flexibility in terms of using renewable energies to supply electricity. If a heat pump is operated with green electricity, its operation can be almost climate-neutral. This is a crucial point in terms of decarbonizing the building sector.
5. Cost aspects: investment and operating costs
Although the purchase costs for a heat pump are higher than for conventional heating systems such as gas or oil heaters, these additional costs are often amortized over the years due to the lower operating costs. Since heat pumps require significantly less electricity than conventional electric heating systems and do not use any fossil fuels, running costs are lower.
In addition, many countries have government funding programs and subsidies for the installation of heat pump systems. This financial support can cover a significant portion of the initial investment and makes switching to this technology even more attractive.
6. Challenges when using heat pumps
Despite their many advantages, there are also some challenges when using heat pumps. One of them is the dependence on the outside temperature for air heat pumps. While these systems work very efficiently in mild weather, their performance decreases somewhat in extremely low temperatures. Air heat pumps are therefore particularly suitable for regions with a temperate climate or as a supplement to other heating systems.
Another challenge is that older buildings are often poorly insulated and therefore require higher flow temperatures to be adequately heated. In such cases, it may be necessary to renovate the building's energy efficiency or choose a hybrid solution in which the heat pump is combined with another heating system.
7. The role of the heat pump in the energy transition
The importance of heat pumps will continue to increase in the coming years, especially in the context of Europe's climate goals and the phase-out of fossil fuels. The EU has set itself the goal of reducing CO₂ emissions to zero by 2050 - a goal that is hardly achievable without a nationwide switch to sustainable heating technologies.
Heat pumps play a central role in this because they not only work efficiently, but can also be combined with renewable energies. In conjunction with solar power systems or wind power plants, they can make a significant contribution to reducing energy consumption in the building sector.
Additionally, technological advances are expected to further improve the efficiency and performance of heat pump systems. New developments such as high-temperature heat pumps could make it possible to heat older buildings efficiently without extensive renovation work.
8. A promising technology with great potential
Heat pumps offer an extremely efficient and environmentally friendly alternative to traditional fossil fuel-based heating systems. With efficiencies of up to 500 percent, they far exceed oil and gas heating systems and at the same time help reduce CO₂ emissions. Their performance is particularly impressive in cold climates such as Scandinavia.
Despite some challenges - especially in older buildings or extremely cold outside temperatures - heat pumps are a pioneering technology with great potential for use in new buildings as well as renovated existing buildings.
With further technological advances and increasing use of renewable energy, this technology is expected to become even more widespread in the coming years - an important step towards a climate-friendly future.
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