The House of Lords Environment and Climate Change Committee opened an inquiry this year into Dunkelflaute and the risks of electricity intermittency and began taking oral evidence this week. The committee wants to know whether the UK has enough dispatchable generation, storage, and demand flexibility to keep electricity supplies steady during an extended renewable shortfall and how large that gap could become by 2030 and 2050. The inquiry lands as the UK pursues its Clean Power 2030 target while electricity demand is set to climb from electrifying transport, buildings, and industry.
The government's own Clean Power 2030 Action Plan calls for 43 to 50 gigawatts of offshore wind, 27 to 29 gigawatts of onshore wind, and 45 to 47 gigawatts of solar by 2030, backed by 23 to 27 gigawatts of battery capacity and 4 to 6 gigawatts of long-duration storage, according to the plan's main report published by the Department for Energy Security and Net Zero. Government scenario modeling has put the dispatchable and long-duration flexible capacity the system could need by 2030 to cover extended low-renewable periods specifically well above what batteries and everyday demand shifting alone can provide. The committee's inquiry is effectively asking whether the plan closes that gap in practice or only on paper.
Gas Stays in the Picture Longer Than the Headline Targets Suggest
Britain currently runs on roughly 35 gigawatts of unabated gas capacity, and the Clean Power 2030 strategy plans to keep about the same amount available in 2030, using it less often as lower-carbon alternatives scale up. The committee is asking specifically what role gas fitted with carbon capture would need to play during a severe Dunkelflaute event and what stands in the way of retrofitting the plants Britain intends to keep. The government's July 2026 update to its Clean Flexibility Roadmap describes hydrogen-to-power, carbon-capture generation, and biomethane as technologies capable of running continuously for days or weeks, exactly the kind of coverage batteries cannot provide once an event stretches past a few hours.
The Harder Question May Be Who Pays to Build Rarely Used Capacity
Technology readiness is only one part of the inquiry. The committee is also asking whether current electricity markets give companies enough reason to build assets that could prove essential during a rare multi-week shortfall while sitting mostly idle the rest of the year, a business case that does not fit neatly into a normal capacity market. That mismatch is not unique to Britain.
Rising load variability and price swings are compressing grid margins in other markets facing the same underlying math, and emerging multi-day storage chemistries like iron-air batteries are being developed specifically to fill the gap batteries built for daily cycling cannot cover. Firm, dispatchable capacity has been drifting back toward the center of grid planning in those same markets. The UK has already tested one answer of its own: a cap-and-floor mechanism meant to give long-duration storage developers enough revenue certainty to justify construction after the government identified revenue uncertainty and long build times as the main barriers holding pumped-storage hydro back. Whether that mechanism, or something closer to a strategic reserve, is enough to get the remaining gigawatts built is the question this inquiry now has to answer before much more of Britain's electricity supply depends on it.
