Air conditioning - the blind spot in the UK’s heat decarbonisation strategy?
This year, the UK experienced unprecedented weather - temperatures above 40°C were recorded for the first-time during the July 2022 heat wave.
Demand for air conditioning (AC) will increase as people look for measures to help them cope with heat stress. As the climate becomes warmer, cooling will become an increasingly important issue. This is a market that will grow in coming years, and this growth will need to be done in a carbon-neutral way if we are to meet our Net Zero ambition.
There are synergies between heating and cooling which could be exploited, allowing for a cost-effective, integrated strategy for decarbonisation.
We have been surprised by the lack of attention to cooling of homes and buildings in the UK Government’s Net Zero strategy.
1. The government’s Net Zero Strategy focuses on heat decarbonisation
As shown in the figure below, heating buildings contributes to 23% of total UK greenhouse emissions. 70% of UK heat demand is supplied using natural gas and, moving forward, the Government looks to phase out gas boilers and facilitate the adoption of low-carbon heat technologies - such as heat pumps, heat networks and potentially hydrogen. To achieve this, the Government has allocated over £10 billion to heat decarbonisation schemes.
Figure 1 - UK emissions by sector 2019.
Source: BEIS (2021) Heat and Building Strategy
2. But, as temperatures rise, demand for cooling is set to increase dramatically
Some studies estimate that at least 5% of total UK electricity demand is used to power AC. The majority of demand comes from office buildings, as shown in the figure below.
Figure 2 - Energy consumption for cooling demand across different building types
As temperatures rise, cooling demand is predicted to rise significantly. A Government report published in 2021 explored three different pathways which cast light on the way cooling-related energy demand might evolve:
“No Intervention”: a combination of portable cooling and cost-effective passive cooling measures, such as internal blinds and night purging.
“Passive First”: Government intervenes to promote higher cost, passive cooling measures, such as shading film on windows and heat reflective walls.
Efficient Technologies: Government intervenes to support deployment of efficient cooling systems.
Figure 3 - Modelled annual cooling energy demand for the UK funder different climate change scenarios
Source: BEIS (2021), Cooling in the UK
In a situation where temperatures rise significantly, and under a No Intervention scenario, energy demand for cooling could increase by a third by 2050, and by 60TWh by 2100. By intervening (as envisaged under the Passive First approach), the Government could significantly reduce energy demand to around 28TWh (a 53% cut) and save around £40bn by 2050.
A wide uptake of cooling systems may have other consequences:
It is possible we will see an increase in the carbon emissions from cooling by as much as a third by 2050 (assuming a constant energy mix).
At a household level, the upfront costs of installation could be as high as £1,500 per room. This might even lead to the extension of winter fuel poverty measures to summer cooling measures.
The additional demand will place a strain on the electricity infrastructure during peak times.
We found it surprising that cooling is only mentioned six times in the UK’s Government Net Zero Strategy. We think this might be a mistake. There are good arguments for anticipating the costs and impact of a rise in cooling demand. In addition, there are important synergies between heat and cooling decarbonisation which can be exploited.
3. The current heat decarbonisation approach could lead to missed opportunities
The table below summarises key synergies between heat and cooling.
Table 1 - Synergies between heat and cooling that can be exploited
We consider there is a risk that investments to decarbonise heat are not used as effectively as possible. We think we might need an integrated heat and cooling decarbonisation strategy.