Heat Pumps: A Clean Energy Solution or Costly Investment?

Exploring the Potential and Challenges of Heat Pump Technology

Heat pumps have become a hot topic in the renewable energy sector, hailed as a promising solution for reducing carbon emissions. However, they have also faced criticism for being too expensive. As discussions around the energy transition intensify, it is crucial to understand the ins and outs of heat pumps to make informed decisions. In this article, we will delve into how heat pumps work, their effectiveness in cold climates, their compatibility with old buildings, the cost comparison with gas boilers, and other considerations. By the end, you will have a comprehensive understanding of heat pumps and their role in the clean energy revolution.

How do heat pumps work?
Heat pumps extract energy from the air, ground, or water and convert it into heat or cool air. This process occurs within the “refrigerant cycle,” which involves evaporation, compression, condensation, and expansion. The collected heat is used to turn the refrigerant fluid into gas, which is then compressed to a high pressure, resulting in a rise in temperature. The hot vapor passes through a heat exchanger, where it transfers heat to the home’s heating system or air conditioning unit. The refrigerant returns to a liquid state and the cycle begins again. Heat pumps are highly efficient, providing approximately three units of heat for every unit of energy input.

Do heat pumps work in cold climates?
Contrary to popular belief, heat pumps can function effectively in cold climates. Countries like Norway, Sweden, Finland, and Estonia, which experience extremely cold winters, have a significant share of heat pump installations. Even at temperatures approaching -30°C, heat pumps can be more efficient than electric heating. The key factor is the “coefficient of performance” (COP), which measures the heat produced per unit of energy input. While heat pumps become less efficient in colder temperatures, they can still provide heat even in freezing conditions. Ground-source heat pumps may be more suitable for these climates due to the stable soil temperatures.

Can heat pumps be installed in old buildings?
Heat pumps are compatible with any type of building, including old and existing structures, as long as the heating or cooling system is suitable. In the UK, a government-funded project demonstrated that heat pumps can be installed in various types and ages of homes, from Victorian mid-terraces to pre-WWII semis and 1960s blocks of flats. Bath Abbey in England is an example of an old building successfully incorporating a heat pump. Planning permission is rarely an issue, but cost remains a significant barrier for many homeowners.

Do heat pumps cost more to run than gas boilers?
Heat pumps are currently more expensive to purchase and install than gas boilers. An air source heat pump can cost around £10,000 (€11,500), with upfront costs two to four times higher than gas boilers. Additionally, electricity prices are higher than gas prices in many countries. However, the International Energy Agency (IEA) states that heat pumps can save consumers money in the long run and protect them from price shocks. Household savings in Europe can reach up to €840 per year. The affordability of heat pumps depends on national policies and subsidies.

Do heat pumps only work in well-insulated homes?
Heat pumps require proper insulation to maximize their efficiency. While they can operate in homes without extensive renovation, measures to reduce heat loss, such as double glazing and insulation, are beneficial. The lower the heat losses, the more efficiently the heat pump operates. Renovation to reduce heating energy demand is recommended for all heating systems, including heat pumps.

Are heat pumps noisy?
Ground source heat pumps are generally quiet. Air source heat pumps consist of an outdoor and indoor unit. The indoor unit produces sound levels between 18 to 30 decibels, equivalent to a whisper. Outdoor units typically have a rating of around 60 decibels, comparable to normal conversation or moderate rainfall. It is important to note that heat pumps do not run during the summer when no heating is required.


Heat pumps offer a promising clean energy solution, but their high upfront costs and compatibility with existing buildings remain challenges. Despite these obstacles, heat pumps have proven to be effective in cold climates and can save consumers money in the long run. Proper insulation and renovation measures can enhance their efficiency. As technology improves and costs decrease, heat pumps are expected to become a more accessible choice for homeowners. With the right support and policies, heat pumps have the potential to address energy poverty and contribute significantly to the energy transition.