Decarbonising heat, which way to go?

We all know that if we are to stop global warming, we need to significantly reduce our carbon emissions. Heating is central to our lives - we rely on it for comfort, cooking and washing. But it also is responsible for over a third of carbon emissions in the UK. To meet our climate change commitments we must decarbonise nearly all heat in buildings.

This is easier said than done. Just before Christmas, the Governemnt published its ‘Transforming Heating’ report. I’ve talked a lot in my blogs over the past year about what we need to do now to decarbonise heat in homes, but this report looks further ahead to support the development of a long-term policy framework for heat. In short it looks at whether we should head for a hydrogen or electrification future.

The report states that ‘there are a range of technologies which have the potential to offer low carbon heating choices in the future, but there is no consensus on which technologies will be able to achieve this most economically and effectively at the scale required’. The report, whilst it is a useful review of the evidence, does not provide a clear direction of travel.

So, what are the pros and cons of each approach?

The widespread use of electric heating has the potential to deliver very deep reductions in carbon emissions, extending beyond the levels likely to be required by 2050. Given that Minister Clare Perry has recently asked the Committee on Climate Change how the UK could meet the 1.5oC Paris target, the option of reducing emissions further than the current targets should be kept open.

The widespread use of hydrogen on the other hand will only meet our current 2050 commitments and is unlikely to deliver savings above and beyond these. To allow hydrogen to be used across the country, firstly physical testing and trialling is still required to prove the safety and feasibility of converting the gas network. Secondly, the deployment of carbon capture and storage is essential and is currently under-developed. Without carbon capture and storage emissions will increase as a result of the switch to hydrogen produced from methane. Finally, the report states that ‘The ultimate depth of the emissions reduction potential of hydrogen is unclear’. Should we really be putting our decarbonisation hopes in a technology with unclear potential, that is unknown and that has some safety concerns?

Heat pumps are an established and proven technology. The Committee on Climate Change has focused on heat pumps as the primary option for heat decarbonisation due to their high efficiencies. They are widely used in other countries and are already deployed in UK homes across the country.

We recognise that the widespread uptake of heat pumps will require the development and reinforcement of infrastructure to distribute low carbon electricity. However, this work will be needed to support the roll out of electric vehicles.

Both routes, hydrogen and electrification, will require the replacement of appliances and disruption to consumers. As recognised by the report, the electrification of homes could require the replacement of heat emitters and hydrogen conversion is likely to require multiple home visits and reduced consumer choice as conversion is likely to take place at a specific time.

Action taken today will lay the foundations for the widespread adoption of low carbon heating. In the new year we will be publishing our own policy paper which provides some recommendations for the short term. We hope that this will feed into the government’s new heat decarbonisation roadmap that will be published in the next 18 months. 2019 will be an important year for policy and we look forward to an exciting few months working with policy makers, parliamentarians and industry to develop the policy framework required.

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