Building decarbonisation transition pathways

Robert Lowe & Tadj Oreszczyn

Summary

The problem of decarbonising heating in buildings has been studied for more than 20 years, but there is still no settled consensus on strategy or choice of technology. There is consensus that the problem requires analysis of the whole energy system. While there is currently much interest in the conversion of the gas grid to hydrogen as a route to heat decarbonisation, recent literature based on whole system analysis appears to indicate that heat pumps are likely to offer the cheapest decarbonisation option overall. Each new installation would achieve an immediate factor-of-three reduction in emissions, with the promise of close-to-zero emissions by 2030, as a consequence of a process that now appears unstoppable – the decarbonisation of electricity generation.

Although many dwellings would also benefit from additional insulation to increase health and comfort, the overall role of insulation in reducing emissions due to heating in the UK is likely to be secondary. High levels of insulation are not essential to the deployment of heat pumps and are only likely to be cost effective in easy-to-treat properties.

But technology choice is not an either-or question. Combinations of technology, such as hybrid heat pumps, and deployment of large heat pumps in district heating systems, offer obvious advantages. And even though the role of hydrogen as a vector for supplying heat to individual homes appears limited on overall cost grounds, hydrogen or hydrogen-derived fuels are likely to play a strategic role in providing backup for the electricity grid at multiple levels, in particular, for the very long-term energy storage that will be needed from about 2040.

Sifting through the multiple combinations and configurations of technologies that are, and will become available over the coming 30 years will be an on-going activity. In this context, a key recent development is an understanding that technology selection has to involve an appreciation of the overall architecture of the energy system. In addition, there is an ongoing need to evaluate and marshal evidence to establish what works and why, and to enhance learning-by-doing by bridging the gaps between research, innovation and communities of practice.

Banner photo credit: Alireza Attari on Unsplash