Britain could dramatically reduce its reliance on gas-fired power by using depleted offshore oil and gas reservoirs to store hydrogen, according to new research from Durham University.
The study models a high-storage pathway in which geological storage capacity reaches 3,659 TWh by 2040, enough to cover more than seven years of projected UK electricity demand at 2040 levels.
The figure, however, needs context. The modeled 3,659 TWh represents a combination of depleted offshore fields and additional salt-cavern capacity. About 2,582 TWh comes from depleted fields in the Irish Sea, Southern North Sea, Central North Sea and Northern North Sea, with the remainder coming from potential salt-cavern development. The researchers treat this as an upper-bound storage scenario rather than a forecast of what Britain will necessarily build.
That distinction matters because Britain’s current hydrogen-storage strategy remains focused heavily on salt caverns. The country’s largest existing offshore gas-storage asset, Rough, is being repurposed for hydrogen, but broader use of depleted reservoirs has yet to become a central element of national planning.
The attraction of depleted fields is scale. Previous research has already identified substantial theoretical hydrogen-storage potential in offshore UK gas reservoirs. A 2021 Applied Energy study estimated up to 2,661.9 TWh of potential capacity in offshore UK gas fields, while noting that only a small number of fields could theoretically meet seasonal storage requirements for domestic heating.
The newer modeling focuses on electricity-system flexibility. Rather than relying on annual averages, the researchers modeled supply and demand at half-hourly intervals while accounting for weather variability and rising electricity consumption from technologies such as electric vehicles, heat pumps and data centers. Under lower-storage scenarios, hydrogen storage became saturated, limiting the amount of surplus renewable electricity that could be converted into hydrogen.
That is the central argument for geological storage. Britain’s growing wind fleet can produce large volumes of electricity when weather conditions are favorable, but short-duration batteries cannot economically cover every prolonged period of low renewable output. Hydrogen can instead convert surplus electricity into a storable fuel and potentially return that energy to the power system during extended periods of low wind and solar generation.
The modeling found that gas generation could fall to around 1% of electricity generation by 2030 across the scenarios examined. Only the high-storage pathway, however, eliminated the modeled need for conventional unabated gas power stations by 2040.
The potential therefore extends beyond storage volume. Depleted reservoirs could provide seasonal flexibility close to offshore wind resources and existing energy infrastructure, although repurposing them would require significant investment in wells, pipelines, compressors and other equipment. Recent research on a UK Continental Shelf depleted gas reservoir has demonstrated technically promising results, including approximately 82% hydrogen recovery in a modeled cyclic-storage configuration, while finding acceptable geomechanical behavior for the specific reservoir studied.
The geological case is not risk-free. Hydrogen can interact with reservoir fluids and rock, while microbial activity can reduce recoverable volumes or affect gas quality. Research on North Sea chalk reservoirs found that biotic processes could result in hydrogen losses, although the modeled maximum in that study was below 0.6% per year. Reservoir-specific testing is therefore essential rather than assuming that every depleted field is suitable.
For Britain, the strategic question is increasingly about how much renewable electricity can be converted into firm energy rather than simply how much renewable capacity can be installed. Geological hydrogen storage could provide a large seasonal buffer, but its value depends on developing the entire chain at the same time: renewable generation, electrolyzers, hydrogen infrastructure, storage reservoirs and hydrogen-fired generation.
That makes the future of depleted North Sea fields an infrastructure decision as much as a hydrogen decision. The assets that once supplied Britain’s gas could potentially become part of a system designed to store surplus wind energy and return it during periods when the weather no longer cooperates.
