Decarbonising building heating and cooling: Designing a novel, inter-seasonal latent heat storage system

The global heating and cooling demands have increased to mitigate the effects of the rise in extreme weather events due to climate change. This has led to an increase in global greenhouse gas emissions due to the use of fossil fuels to meet these demands. The current study evaluates how an alternative low-carbon heating and cooling system may provide thermal comfort in residential buildings, specifically in regions that have a humid temperature oceanic climate-for example, the United Kingdom. To meet the net-zero emissions targets set in the United Kingdom by 2050, greenhouse gas emissions generated from heating in residential buildings must fall by 95 %. The leading decarbonisation strategy proposed by their government requires the electrification of the heating system through the installation of heat pumps. Consequently, the average electricity consumption per household is expected to increase. This will impose considerable pressure on electricity networks to source additional (ideally renewable) capacity, which will ultimately be costly. To circumvent this issue, the current study proposes a novel alternative method of providing nearly zero-carbon space and water heating, that can operate almost independently of the electricity grid. This requires the use of solar energy as the thermal energy source, and a solid-liquid phase change material as an inter-seasonal energy storage medium. A design optimisation study was thereafter carried forward to showcase the capability of such a system for a semi-detached house in London, United Kingdom.