Rough is not a tank. It is a depleted natural gas field about twenty miles off the East Yorkshire coast, three hundred metres below the sea bed, with thirty wells drilled into a porous rock formation that once held its own gas. Production licences were issued in 1964; gas began flowing ashore to Easington in 1975. By 1980 the field was about a third depleted, and British Gas Corporation bought it with a different purpose in mind. In 1983 the decision was made to convert it into a strategic storage site. Pump gas in during the summer when prices are low, hold it under pressure in the rock, pump it back out in winter when demand and prices spike. The facility opened in 1985 with capacity for 100 billion cubic feet, which in 2021 was still nearly double Britain's other storage combined.

Through the 1990s and 2000s ownership shuffled: British Gas, then BG Storage as part of BG Group, then sold to Dynegy in 2001, then Centrica in 2002 for £304 million during Dynegy's near-bankruptcy crisis. Centrica Storage Ltd became the long-term operator. Then in 2016, routine integrity testing revealed corrosion and stress problems in the wells. The repairs were possible but expensive. The government would not pay. In June 2017 Centrica announced closure, betting that liquefied natural gas imports and pipeline gas from Norway would cover Britain's needs. Energy analysts warned of volatile winter prices. Few in government listened. By spring 2022 the assumptions of 2017 looked very different.

When Russian troops crossed into Ukraine on 24 February 2022, the European gas market re-priced overnight. Prices reached levels that had been considered impossible a year earlier. Centrica filed in June 2022 to bring Rough back into service. The North Sea Transition Authority approved in July. By August the safety inspectors had signed off, and on 28 October 2022 the facility partially reopened with 20 percent of its original capacity available. That alone increased total UK gas storage by about 50 percent. Centrica claimed in its 2024 annual report that the reopening had been done for less than £10 million and had produced £653 million in operating profit between 2022 and 2024. They also briefed the media, simultaneously, that losses were unsustainable without a government price-smoothing mechanism. Both can be true. Energy markets are strange.

Offshore, the facility is two complexes about 2 km apart. Rough Alpha is two platforms connected by bridges. Rough Bravo is three platforms connected by bridges. From the Easington shore, a 36-inch pipeline carries gas out to Bravo, where two Rolls-Royce Avon gas turbines - originally designed in the 1940s as aircraft engines for the de Havilland Comet - drive compressors that force gas down into the reservoir at high pressure. The same wells reverse the flow in winter. Nearly two hundred staff and contractors keep Rough running. The Easington onshore terminal that handles compression and processing forms part of the larger Easington Gas Terminal complex, which when running flat out can inject 125 million cubic metres per day - roughly forty percent of Britain's daily gas demand. The whole strange story is a reminder that in modern energy systems, the most important infrastructure is sometimes invisible: an old gas reservoir buried beneath cold North Sea water, breathing in and out with the season.