The UK urgently requires a significant expansion of its energy storage capacity to achieve its goal of a clean power system by 2030, according to a new analysis by Drax Electric Insights.

The report, conducted in collaboration with academics at Imperial College London, highlights that a substantial portion of wind-generated electricity is currently being wasted.

In 2024, Britain reached a historic milestone, with wind power becoming the country's largest source of electricity, accounting for 31% of total generation and surpassing fossil fuels for the first time in 140 years. However, despite this achievement, 8.3 terawatt-hours (TWh), or approximately 10% of generated wind power, was curtailed due to grid congestion, costing consumers nearly £400 million. This wasted energy is enough to power over two million homes.

The report emphasises that scaling up energy storage capabilities, such as long-duration energy storage (LDES) and battery energy storage systems (BESS), alongside grid infrastructure improvements, is crucial. These solutions would allow excess wind power produced during periods of low demand to be stored and released when needed, reducing reliance on gas during 'dunkelflaute' periods – periods of cold, calm weather. Without significant investment and policy support, the UK risks losing vast amounts of clean energy.

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Dr Iain Staffell of Imperial College London, lead author of the Drax Electric Insights report, said: "The rapid continued growth of wind power generation should give us cause for optimism on the journey towards clean energy, but that growth presents its own very real and different challenges. Last year we saw a 17% reduction in emissions compared to 2023, but with more wind comes more intermittency. This was evident across the back end of 2024 and early 2025, with three separate periods of cold, calm weather – known as 'dunkelflaute' – exposing Britain's reliance on costly imported energy and drawing down the nation's gas storage to 'concerningly low' levels."

He added: "Investment in intermittent renewables such as wind and solar is helping us reduce fossil fuel levels in our power generation mix, but without large-scale energy storage and grid upgrades, we will continue wasting clean energy and paying the price for it, especially during long cold snaps and windless conditions."

The report also noted that curtailment of wind energy has doubled in a year, rising from 5.5% to over 10%, primarily due to Scottish wind farms producing more energy than the grid can transmit to demand centres in England.

Ian Kinnaird, FlexGen Assets Director at Drax, said: "The UK government has set ambitious targets for energy storage and grid reinforcement, but the pace of deployment must accelerate to match the rapid growth of renewable generation. Policy incentives, streamlined planning processes, and investment in medium and long-duration storage technologies will all be critical in ensuring Britain fully capitalises on its renewable energy sources."