UK industry sectors released approximately 61mn tonnes of CO₂e from production processes and fuel combustion alone in 2019. This figure would be significantly higher if emissions from electricity generation and fuel supply were included. These industry sectors account for approximately 18% of the nation’s total annual energy consumption.   

Of the 270 TWh consumed in 2019, 54.1% and 4.1% of energy were used to meet heating and cooling demand, 146 TWh and 11 TWh respectively. The heating demand – representing 23.2% of the UK’s total heating demand – is currently met by a combination of 50% gas, 26% electricity, 5.5% solid fuel, 4.1% oil, 9.6% bioenergy and waste, and 5.5% direct heat. This energy is used for low- and high-temperature processes (37.7% and 22.6%, respectively), 12.3% drying and separation processes, 12% for space heating, and 14.4% other industrial uses, while the cooling demand is supplied entirely by electricity. These industrial processes collectively release approximately 62 TWh/y of waste heat through exhaust, cooling liquid and radiant heat, according to a 2021 UK government study.  

Waste heat 

The potential for capturing, utilising and storing low-grade waste heat from gaseous waste streams for efficient energy recovery, using thermochemical materials, was explored in Swansea University research. Demonstrating that low-grade waste heat from industrial sites like Tata Steel’s plant in Port Talbot could supply heating for approximately 33,000 homes annually, where the transport of this waste heat within a 30-mile radius would be feasible.   

Given the typically low energy efficiency of industrial air compression (around 10%, which accounts for about 10% of the total industrial energy use) an enhanced air compression system could offer significant improvements. The system developed in University of Birmingham research led by Yulong Ding, which integrated compressed air and heat storage, could boost efficiency to 35% and reduce cost by up to 40%. The mobile thermal energy storage (MTES) technology also developed in that project, utilising composite phase change materials (CPCM) to store and transport waste heat, could further support decarbonisation of industrial heat.  

The waste heat recovery case study carried out by a Teesside University team demonstrated that using heat pump systems for crisp frying could heat vegetable oil to 160°C, achieving a payback period of just five months.   

Sustainable fuels 

Hydrogen-based fuels offer significant potential as zero-carbon vectors, especially in process heating applications.  

An Imperial College London project converted internal combustion engines to operate on hydrogen fuel. The research team developed a novel method for early detection of impending thermoacoustic oscillations in gas turbines (which pose a limiting factor on the introduction of hydrogen fuel), and proposed a new approach to controlling the ignition of lean mixtures using a zero-carbon additive, hydrogen peroxide (H₂O₂).   

Complementing this, a project at Cardiff University examined the transition from natural gas to hydrogen, showing that heat transfer in hydrogen flames would rely more on convection than radiation, potentially impacting certain industrial processes. The researchers concluded that training for operators, proof-of-concept testing and dedicated R&D facilities are essential resources to support the fuel-switching transition.

The model developed in a Durham University project led by Sumit Roy for a metal hydride compressor integrated with a protein exchange membrane (PEM) electrolyser demonstrated potential for green hydrogen generation with increased efficiency through heat recovery.  

For different fuel switching options to be viable, appropriate infrastructure needs to be in place, depending on the location. This is especially important for dispersed industries responsible for 55% of emissions that may not have access to increased power, hydrogen production facilities or CO₂ transport.   

Analysis of technology and demand scenarios, as demonstrated in another University of Birmingham project led by Jonathan Radcliffe can help identify where future infrastructure could enable fuel switching across the UK. It estimates an increase in electricity demand in all regions by 50–70% compared to current gas demand. Hydrogen demand would range from 8–37% of existing gas levels, predominantly near Merseyside, Humberside and other major industrial conurbations (West Midlands, West Yorkshire). Additionally, demand for carbon capture, utilisation and storage (CCUS) would remain steady, especially for cement and brick sectors.   

By integrating carbon capture and waste heat recovery from flue gases in steel and chemical sectors, and producing hydrogen, the system investigated in a University of Oxford project not only achieved a 40% energy efficiency gain and lowered emissions, but also demonstrated scalability through a study of a pilot system.   

Ammonia also presents a viable alternative as a hydrogen energy carrier, particularly in industries reliant on energy-intensive combustion processes where hydrogen infrastructure is underdeveloped and hydrogen combustion poses challenges. Assessing the feasibility of using ammonia as a working fluid or fuel, in applications like steelmaking or power generation, could unlock new pathways for decarbonisation. Industries are encouraged to conduct pilot studies to evaluate the practical use of ammonia in their operations, particularly in settings where conventional hydrogen use may not be feasible.   

Exploring ammonia’s feasibility as a combustion fuel, a University of Cardiff research team identified strategies for reducing NO_x emissions by controlling the air/fuel ratio at varying pressures, proposing diverse injection systems tailored to specific applications and underscoring the need for adaptable, scenario-specific solutions.   

Additionally, industries should explore adopting scalable energy solutions, such as the trans-critical CO₂ heat pumps tested by a Teesside University research team, which have demonstrated substantial CO₂ savings while offering relatively short payback periods.  

Industrial collaboration is recommended to develop testing and proving resources for hydrogen infrastructure, to reduce uncertainties and foster a more widespread adoption of hydrogen-based solutions.

Energy efficiency 

A Durham University project led by Janie Ling-Chen modelled heat and power demands of a dynamic hybrid cluster, assessing heat electrification, renewables and fuel switching in both grid-connected and island modes. The results underscore substantial energy efficiency and emissions reductions through optimised generator operations (achieving up to 95% savings in steam losses and a 25% reduction in primary energy demand) and electric steam boiler integration (reducing costs by 75% and emissions by 50%) while using green hydrogen further cuts emissions but significantly increased costs.  

The UK steel industry’s transition to electric arc furnaces also presents an ideal opportunity to adopt biochar as a carbon-negative coal alternative, which has lower contamination levels such as sulphur content. However, achieving this integration successfully will require a well-developed biomass/biochar supply chain to avoid costly retrofits in the future, found a University of Lincoln project.   

Training and skills development 

To implement advanced low-carbon technologies effectively, there is a need for in depth, specialised content and reliable information to equip industry professionals with the skills and awareness of industrial decarbonisation options; a culture of professional development; and greater financial support from industry and government to ensure the workforce can address decarbonisation challenges.   

The industry-focused continuing professional development (CPD) module developed University of Durham research led by Huashan Bao featured real-world industrial case studies, upskilling industry professionals whilst enhancing their awareness and understanding of low-carbon heating and cooling technologies to bolster the decarbonisation agenda. The Decarbonisation of Heating and Cooling eLearning Course is available through the RPS Learning Hub.  

In conclusion 

Harnessing waste heat can reduce total energy consumption in industrial sectors, improving energy efficiency without compromising production, and significantly lowering greenhouse gas emissions. However, this poses a substantial challenge due to the complexity of bespoke industrial processes employed by different sectors, as well as the high costs associated with energy-efficient equipment and innovative technologies, in addition to the significant knowledge and skills gaps faced by the sectors.   

Industrial collaboration is recommended to develop testing and proving resources for hydrogen infrastructure, to reduce uncertainties and foster a more widespread adoption of hydrogen-based solutions. This collaborative approach could help industries identify optimal strategies for fuel switching, which is critical for hard-to-abate sectors like heavy industry and transportation.   

Other measures to decarbonise industrial sectors include integrating energy storage, transitioning to net zero or low-carbon fuels, increasing the share of renewable energy, electrifying industrial heat and adopting CCUS.   

Since conventional systems are largely reliant on fossil fuels, these strategies will require better understanding through a whole-system approach, predictive analytics and advanced control, retrofitting production plants and redesigning operational systems. Thus, achieving net zero will demand not only technological innovation, but also cross-sector collaboration, policy support and significant financial investment.  

A full version of this report has now been published on the IDRIC Knowledge Hub. Since its launch in 2021, IDRIC has funded 100 projects exploring the key dimensions of the whole system of industrial decarbonisation. That work is brought together in the 2025 Frontiers Report series.    

• Further reading: ‘Decarbonising UK industry: IDRIC’s transformative impact’.  Since its launch in 2021, IDRIC has developed an influential network of over 700 industries, trade associations, governmental/public bodies and research institutions, to accelerate the pace and scale of industrial decarbonisation. As the organisation nears the end of its current phase of work, its Director, Professor Mercedes Maroto-Valer, also the Robert Buchan Chair in Sustainable Energy Engineering at Heriot-Watt University, looks back over four busy years. 
• 'Research update on.... policy and governance’. The energy transition is not only about technological innovation; the ways in which public policy incentivises and regulates decarbonisation initiatives bear greatly upon society, writes Benjamin Sovacool, Professor of Energy Policy, University of Sussex.