Decarbonisation of Heating in UK Non-Domestic Buildings

Catherine Bottrill, from our technical partners Pilio, explores the pros and cons of new strategies of sustainably heating non-domestic buildings in the UK.

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Heating non-domestic buildings in the UK is a significant contributor to carbon emissions, responsible for around 17% of the country’s greenhouse gas emissions.

This figure highlights the importance of transitioning away from fossil fuels like natural gas, which still powers the majority of commercial and industrial heating systems, to more sustainable options. Decarbonising the heating sector is essential for the UK to meet its legally binding goal of achieving net-zero carbon emissions by 2050.

The Carbon Impact of Heating

As of now, most non-domestic buildings in the UK use gas-fired boilers for space heating, water heating, and industrial processes. Natural gas, a fossil fuel, emits 0.204 kg of CO2 per kilowatt-hour (kWh) when burned. With millions of square metres of office space, retail environments, and industrial units across the country, the cumulative emissions from heating these buildings are substantial. It is estimated that the UK’s heating sector overall contributes around 85 million tonnes of CO2 annually, with a significant portion attributable to non-domestic properties.

To decarbonise this sector, the UK is considering two main strategies: heat pumps and synthetic fuels like hydrogen and methane. Both approaches have potential, but they vary significantly in terms of infrastructure needs, cost, and carbon savings.

1) Heat Pumps

Heat pumps are widely seen as the cornerstone technology for decarbonising building heating. They operate by extracting heat from the air, ground, or water and using it to heat spaces. Heat pumps are highly efficient heating systems. For every 1 kWh of electricity they consume, they typically produce 3-4 kWh of heat. In comparison, gas boilers convert about 90% of the energy in the gas they use into heat, meaning they are less efficient than heat pumps. 

The use of heat pumps could significantly reduce emissions, especially as the UK’s electricity grid continues to decarbonise. As of 2023, around 56% of UK electricity comes from low-carbon sources, including renewables like wind and solar. By leveraging this cleaner energy, heat pumps can dramatically cut the carbon footprint of heating, provided they replace natural gas and oil systems.

Challenges with heat pumps include high upfront costs and space requirements for installation, particularly in older buildings that may not be energy efficient. Additionally, retrofitting older buildings with heat pumps may require upgrading insulation and radiators to work efficiently at lower operating temperatures compared to traditional boilers. Despite these hurdles, heat pumps are a critical part of the UK’s decarbonisation roadmap and are supported by government schemes such as the Clean Heat Grant.

2) Synthetic Renewably Generated Fuels (Hydrogen and Methane)

An alternative pathway to decarbonising heating is the use of synthetic renewably generated fuels like hydrogen or renewable methane (biomethane). These fuels can potentially replace natural gas in existing infrastructure with minimal changes, making them an attractive option for buildings that are harder to retrofit for heat pumps.

Hydrogen has been touted as a future fuel for heating, with green hydrogen (produced from renewable electricity) offering a zero-carbon alternative to natural gas. It can be combusted in boilers or used in fuel cells to provide heat. However, challenges include the lack of infrastructure for distributing hydrogen and the high cost of production, as green hydrogen is currently expensive compared to fossil fuels.

Biomethane is another option. It can be produced from organic waste through anaerobic digestion and injected into the existing gas grid. While biomethane has a lower carbon footprint than natural gas, its supply is limited by the availability of suitable feedstock. Moreover, like hydrogen, it still results in some emissions when combusted, though these are much lower than fossil methane.

Conclusion

Both heat pumps and synthetic fuels are viable pathways for decarbonising heating in UK non-domestic buildings. Heat pumps offer immediate carbon savings by using electricity from an increasingly green grid, but they require substantial investments in infrastructure and building upgrades. On the other hand, synthetic fuels like hydrogen and biomethane provide a more gradual transition, allowing the continued use of existing gas infrastructure but face production challenges and resource constraints.

The most likely future scenario will involve a combination of both technologies, with heat pumps leading the way in new and retrofitted energy-efficient buildings, while hydrogen and biomethane serve as transitional fuels in harder-to-decarbonise sectors.

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Resources

• If you are in a historic building there will be additional considerations, check out this helpful guide for case studies and more insights from Historic England.
• If you are a National Portfolio Organisation, and would like to know about upcoming programmes and sessions you can join, please sign up to our newsletter for the Arts Council England Environmental Programme.
• If you are an organisation keen to do more around energy reduction of your cultural buildings, you can also sign up to our free Transforming Energy – Buildings Net Zero Energy programme. Here you can find a programme with self-service resources, opportunities to seek support from our technical partners, Pilio, and training on good energy management practice provided by Julie’s Bicycle.