Industrial heating accounts for around 14 percent of UK emissions, but around half of the energy used in UK industry is lost as waste heat, according to a new report. Analysis supported by expertise from Heriot-Watt University shows this heat could be captured and reused rather than released.
The report by the Royal Society, Unlocking thermal energy: Capture, storage and re-use of industrial waste heat, sets out how reusing thermal energy could be a huge opportunity for the UK – to cut emissions, reduce operational costs for businesses, and accelerate progress towards net zero.
Heat loss is especially notable in sectors such as steel, cement, glass and chemicals, where materials are often heated to temperatures of up to 2,000°C and then cooled. Large amounts of thermal energy are lost to the environment as a result.
Despite a move from fossil fuels towards cleaner sources of energy, significant heat loss will continue unless new systems are put in place to capture, store and reuse it.
Professor Mercedes Maroto-Valer OBE, Deputy Principal for Global Sustainability at Heriot-Watt University and Director of the UK Industrial Decarbonisation Research and Innovation Centre (IDRIC) is one of the report’s contributors.
Speaking at its launch, she said: “This report shines a light on one of the UK’s most overlooked energy resources. Industrial waste heat is often treated as an inevitable by-product, yet it represents a vast reservoir of untapped potential.
“The findings make clear that if we design our future infrastructure with fuel switching and thermal efficiency in mind, the UK can accelerate its journey to net zero while strengthening industrial competitiveness.
“This is a moment we cannot afford to miss.”
The report proposes a national approach to thermal energy re-use based on “heat cascades”. In this way, high-temperature waste heat would be distributed to progressively lower-temperature users.
Heat used in the original industrial process could be captured and reused on-site. It could then be shared across industrial clusters with co-located facilities before finally supplying heat networks to warm homes and public buildings.
This would not only reduce the need for additional energy to heat these spaces but also help ease pressure on electricity demand as more heating becomes electrified.
Furthermore, new sources of waste heat, such as electrolytic hydrogen production, carbon capture and storage, and data centres, will also emerge as the UK transitions to net zero, making the need for integrated heat-reuse systems even more urgent.
The report warns that failing to integrate heat capture systems into upcoming industrial changes would risk locking in new technologies that are incompatible with future heat reuse. This could leave UK industries at a long-term competitive disadvantage.
Professor Andy Woods FRS, Head of Institute for Energy and Environmental Flows at the University of Cambridge and lead author of the report, said: “If the UK is serious about reaching net zero, dealing with the vast amounts of industrial waste heat needs to be integrated into decarbonisation strategies now, and not as an afterthought.
“As industry makes the switch from fossil fuels to cleaner alternatives, we have a huge window of opportunity to integrate systems to capture and reuse industrial waste heat into future infrastructure.”
The infrastructure required would include heat capture and exchange systems, heat networks capable of transporting energy at different temperatures, and thermal energy storage technologies.
These would help balance supply and demand, support energy resilience, and enable more predictable operation of industrial sites.
To achieve heat reuse at scale, coordinated action among the Government, industry, regulators, communities, and researchers will be essential, according to the report.
In conclusion, it urges a change of perspective: if waste heat is seen as a valuable national resource, rather than an unavoidable loss, the UK can strengthen its industrial base while making significant progress towards net zero.