Heat pumps are a potentially revolutionary technology; they are able to extract heat from cold fluids (e.g. air or water) by compressing these fluids, increasing the kinetic energy and therefore temperature. By using heat sources which otherwise would be left to waste such as ambient outside air or waste heat streams, heat pumps have the potential to revolutionise both domestic and industrial processes by massively increasing their efficiency. Why then are heat pumps not in every home and factory?

Domestic market

Domestic heat pumps have seen a significant increase in uptake in recent years. The most common type are air-to-water pumps, utilising outside air as a source to heat water which is then used domestically. This sector dominates the overall global heat pump market, and its growth is likely driven by ambitious nationwide climate targets. Nordic countries such as Norway, Sweden and Iceland, have the fastest rate of increase in adoption in Europe. This is likely driven by their pledges to reduce greenhouse gas emissions by at least 75% by 2050, with heat pumps a very effective way to do so, as they can reduce greenhouse gas emissions by up to a staggering 80% (depending on the percentage of renewable energy used to power the compressor). This figure, however, raises further queries as to why domestic pumps are not installed in every home. One reason for this could be the significant upfront capital investment they require, which creates a critical barrier for many homeowners.

Industrial applications

Although the domestic heat pump market is already experiencing significant growth, its industrial counterpart is still struggling to get off the starting line. This is primarily due to the limited temperature range which heat pumps can provide, as they can currently only upgrade heat by about 2-3x. This limits their maximum output temperature to ~200 °C. Most industrial heat demand requires significantly higher temperatures than this (500-600 °C), so heat pumps have limited applicability in manufacturing processes. There are, however, large research and development efforts in place to create heat pumps suitable which can reach these temperatures, as doing so would revolutionise industry by making much more efficient use of waste heat. However, even for processes within the applicable temperature range, adoption is still low. This is because of a catch-22 of sorts, where industries such as chocolate and confectionery production with a low-temperature, high-volume heat demand do not adopt heat pumps due to a lack of proven evidence of both their effectiveness and longevity. However, in order for this to be shown, manufacturers have to first adopt the pumps and use them for long periods of time, and so the cycle continues.

The heat pump industry has a large potential to disrupt energy generation and utilisation of waste heat streams, but still is in its infancy especially when considering industrial applications. Changing legislation could make all the difference in increasing adoption, so the issue of reducing GHG emissions used in heating falls directly at legislators’ doorsteps.

Written by Joshua Aderanti, who joined RIG as a summer intern in 2023. Find him on LinkedIn here: https://www.linkedin.com/in/joshua-aderanti/