Can thermal storage assist with the electrification of heat through peak shaving?

Abstract

The majority of heat in the UK comes from the combustion of natural gas, and heat is responsible for 37% of the nation’s carbon emissions. Thus the decarbonisation of heat is a major challenge. Electrification is one possible approach to decarbonisation; however, huge increases in the electrical grid’s generation and transmission capacity would be needed to meet the peaks in space heat demand during cold winter weather. Thermal energy storage (TES) may have a role to play in alleviating this problem, by shifting heat demand by hours or longer periods, enabling peaks to be shaved.This work considers the utility of two varieties of thermal energy storage for this application. Adsorption thermal storage (ATS) is a technology offering long term storage at a high energy density, but is a costly and relatively immature option. By contrast, storage of sensible heat in hot water tanks is already widespread, although it has relatively short storage duration and lower density.Here, we simulate the deployment of these technologies in a small residential neighbourhood, in tandem with demand-side management (DSM), to attempt the reduction of peaks in demand. With no storage or DSM, electrification causes peaks to increase by a factor of 2.36. Results so far suggest that both TES technologies have potential to reduce peaks, with a 14% decrease achievable by either 5 m3 of hot water storage, or 0.25 m3 of ATS, in each dwelling. However, it is thought unlikely that adsorption storage is attractive for a purely peak shaving application, given its cost and complexity.