Unlocking thermal energy: capture, storage and re-use of industrial waste heat

It is estimated that over half of the energy used in UK industry is lost as waste heat. There is an opportunity to improve thermal energy efficiency in industry and to re-use surplus heat elsewhere, re-imagining the role of heat in a net zero future. This report explores how waste heat can be captured, transported, stored and re-used, to support decarbonisation, improve industrial productivity and competitiveness, and unlock new sources of low-carbon heat for homes and businesses.

What is industrial waste heat?

Industrial waste heat is thermal energy generated during industrial processes that is not put to productive use and is instead released into the environment. Heat losses are particularly significant in the UK’s foundation industries, including steel, cement, chemicals, glass, paper and ceramics, where materials are heated to temperatures between around 400°C and 2,000°C and then cooled. Even with improved efficiency and a shift to clean energy sources, a substantial amount of waste heat will remain unavoidable. New sources of waste heat are also expected to grow, including from data centres, hydrogen production, and carbon capture and storage.

How could waste heat be re-used?

The report proposes a cascade approach to thermal energy re-use, where heat is used multiple times at progressively lower temperatures. High-temperature heat could first be re-used on-site, then shared across industrial clusters where different industries are co-located, and finally supplied to low-temperature end uses such as district heating and space heating in the built environment.

What is needed to enable heat re-use at scale?

Delivering large-scale heat re-use will require efficient technologies for heat capture and exchange, heat networks capable of transporting thermal energy,, and thermal energy storage to balance supply and demand over time. Alongside technological advances, supportive regulation, planning frameworks, and mechanisms to value, measure and trade surplus heat will be essential. Coordinated action between stakeholders will be needed to overcome high costs and integrate heat re-use into the UK’s wider net-zero energy system.

Further reading

The Royal Society’s report on Large-scale electricity storage highlights the need for whole-system approaches that integrate electricity, heat and fuels, reinforcing the value of reducing wasted thermal energy.

Defossilising the chemical industry addresses the importance of improving energy efficiency and making better use of by-products such as waste heat to cut emissions and costs in energy intensive sectors.