UK Research Highlights Massive Storage Needs for Heat Pump Transition

A new study from the University of Nottingham has warned that the UK will require approximately 175 terawatt-hours (TWh) of energy storage capacity to fully decarbonize domestic space heating through heat pump deployment. The research, set to be published in the journal Renewable Energy in July, analyzes grid-level storage requirements at different stages of heat pump adoption.

Bruno Cardenas, lead author of the study, emphasized the scale of the challenge, noting that meeting future demand for storage represents a "massive undertaking." He drew a contrast with current reliance on gas infrastructure, explaining: "The gas network inherently provides huge storage capacity—simply adjusting pressure in pipelines allows for flexible gas storage. We don’t yet feel the full pressure of the storage challenge because this infrastructure has long supported demand fluctuations."

The analysis projects that a fully electrified heating system would increase the UK’s annual average electricity demand by 26% and peak grid load by 70% compared to today’s levels. The modeled scenario also shows a 4% increase in total energy costs, primarily driven by the need for long-duration storage infrastructure. According to Cardenas, this underscores the urgent need for substantial investment in technologies like underground hydrogen caverns and compressed-air energy storage (CAES).

In the study’s modeled scenario, a combination of 160 TWh of hydrogen storage (sufficient to meet around 220 days of demand) and 15 TWh of CAES (covering approximately 10 days) would collectively provide the required 175 TWh capacity. While batteries were not part of the research scope, Cardenas acknowledged their current role in short-term grid flexibility, noting that this function is likely to remain critical.

The research highlights peak demand fluctuations as a key challenge. Despite heat pumps’ high efficiency, human behavior—such as morning and evening heating surges (5–8 am and post-work hours)—creates pronounced load spikes. Cardenas stated: "These daily peaks are a direct result of synchronized energy use. Even with advanced thermal storage systems in homes and demand-side management, we cannot eliminate the need for large-scale, long-duration storage."

Given the decade-long deployment timelines for technologies like hydrogen caverns, Cardenas stressed the importance of acting now: "Debates about exact storage numbers are natural, but we cannot delay action for perfect data. We know the requirement is in the tens of TWh range—and with virtually zero grid-scale storage currently operational in the UK, the urgency cannot be overstated."

The study’s findings add to growing calls for integrated energy infrastructure planning as the UK accelerates its transition away from gas heating.