Giant batteries will provide surge of electricity storage

Britain’s capacity to store electricity in giant batteries is set to double after dozens of new projects won contracts through a government scheme to keep the lights on.

Developers of battery storage projects with a total output capacity of at least 3.3 gigawatts won contracts to operate from winter 2025-26 through the government’s “capacity market” auction, according to Cornwall Insight, the consultancy.

That is larger than the power output of the proposed Hinkley Point C nuclear plant, although most of the batteries will have the storage capacity to produce that output for only up to two hours at a time.

Tom Edwards, analyst at Cornwall, said the batteries’ capacity was “equivalent to storing enough energy to power 1,792 homes for a year, or powering 1.6 million kettles simultaneously”.

Winners include Intergen’s giant 320 megawatt project at DP World London Gateway on the Thames Estuary in Essex, which is set to be the UK’s biggest, and one of Europe’s biggest, batteries.

The government’s capacity market scheme pays power plant owners a retainer to guarantee they will be available to generate when needed in future winters. Most plants are contracted four years in advance, with final capacity secured one year out.

This week the government held the initial auction to secure power capacity for winter 2025-26, which will result in £1.3 billion being paid to power plant owners that year at a record high price for the advance auction. The lion’s share of the plants to win contracts are for existing gas-fired power plants.

EnAppSys, the consultancy, said the high price reflected that the amount of power plant prequalifying for the auction was a record low, “in part due to the expected closure of much of the existing nuclear fleet”.

EnAppSys estimates that the auction will result in Britain’s battery capacity increasing by about 3 gigawatts to 5.7 gigawatts, while data from National Grid suggests the volume procured could be even higher.

Paul Verrill, director of EnAppSys, said: “Battery project winners are the biggest news in this auction, with many new-build battery projects having chosen the year with the highest ever clearing price for a T-4 auction to come online. This is a major boost in particular for those units that were able to secure long-term contracts.”

Edwards of Cornwall warned that it would “be a challenge to deliver all this on time, especially given the impact of the pandemic on global supply chains”, which was notable because “nearly all battery cells are made in China”.

A spokesman for Intergen said it was “delighted that the Gateway battery storage project has been successful in securing an award in the recent Capacity Market auction”.

“This award is a significant milestone in the project, which will now commence construction in 2023,” it said.