The UK's installed battery storage capacity has surpassed its nuclear generating fleet for the first time, marking a shift in the country's power system as investment in flexible energy infrastructure accelerates, Drax Group said in a report on Thursday.
Battery energy storage system capacity has surged from just 10 megawatts less than a decade ago to nearly 7 gigawatts today, overtaking the combined output capacity of the country's aging nuclear reactor fleet.
The report, produced by academics at Imperial College London, highlights how rapidly storage technologies are scaling as the UK integrates more intermittent renewable generation and responds to rising electricity demand.
Though batteries and nuclear plants serve fundamentally different roles, nuclear provides steady baseload power and batteries offer short-duration flexibility, the crossover underscores a structural shift in how Britain balances its electricity system.
Drax said battery systems are increasingly being deployed to absorb excess electricity during periods of high supply and discharge power within seconds when demand spikes, helping grid operators manage volatility and reduce network constraints.
"Battery storage has become one of the fastest-growing parts of Britain's electricity system," said Dr. Iain Staffell, lead author of the report and associate professor in sustainable energy at Imperial College London.
"The fact that installed battery capacity has now surpassed nuclear generating capacity demonstrates just how rapidly storage technologies are scaling."
Drax said that batteries are already playing an increasingly important operational role in stabilizing the grid, responding almost instantaneously to changes in system conditions, and supporting energy security.
However, Drax said that batteries do not replace nuclear power on a like-for-like basis, given their limited storage capacity, although their rapid expansion signals a broader reconfiguration of the UK power mix.