Field Analysis: £920 million annual cost of ‘curtailment’ could be cut 80% by using existing technologies like battery storage more effectively

• Practice of firing up gas power plants in England and Wales and switching off wind farms in Scotland cost bill-payers £920 million in 2023
• B6 ‘pinch point’ in the UK’s transmission network on the Scottish / English border is the prime culprit, with £670 million of payments made to gas power plants alone in 2023 to overcome this
• Cost of this problem will increase by 2030, with £2.2 billion a year of curtailment costs caused by this pinch point in the network alone, and £3.5 billion a year overall in the UK
• Cost of curtailment could be cut by 80% through more efficient use of technologies such as battery storage to unlock capacity on the existing transmission network

Grid capacity constraints added nearly £1 billion of ‘curtailment’ costs to electricity bills for homes and businesses in 2023 as abundant energy from wind farms was unable to be transmitted to areas of demand. The majority of this cost was down to a single pinch point in the UK’s electricity grid on the Scottish/English border called the B6 boundary. Analysis by energy storage developer and operator Field estimates this boundary alone could cause up to £2.2 billion of curtailment costs by 2030 as the UK’s curtailment problem escalates. Overall UK curtailment costs could reach £3.5 billion by that date₁.

Nearly three quarters of the UK’s total curtailment cost in 2023 came from paying gas power plants in England and Wales to fire up, as capacity constraints on the grid meant cheaper, abundant wind power from Scotland couldn’t be exported south when required. Field’s analysis also reveals that wind farms in Scotland are being curtailed 40% of the time, while transmission capacity across key boundaries in the UK, including the B6 boundary, rarely has more than a 50% utilisation rate, further restricting the flow of electricity.

However, the cost of curtailment to billpayers could be trimmed by approximately 80% if existing technologies like battery storage are used more effectively on the current grid, according to Field’s analysis. Increasing the amount of “intertrip services” the National Energy System Operator (previously National Grid ESO) can buy and using “Grid Booster” batteries would both contribute to tackling the problem, with the latter technology already being deployed in continental Europe and Australia.

To address the specific curtailment problem caused by the B6 boundary on the Scottish/English border, building 10GW of energy storage in key locations across the UK would reduce the estimated £2.2 billion curtailment costs by nearly 90%, Field’s analysis suggests.

In response to the analysis, Field is today calling on the newly-independent National Energy System Operator, Ofgem and the Government to work together to:

1. Prioritise available, cost effective measures like batteries and related services to maximise use of the existing grid.
2. Do this rather than focusing on less practical or new market-based mechanisms such as zonal pricing that will reduce investment certainty, and take a long time to implement.

Commenting on the new analysis, Amit Gudka, CEO of Field, said:

“In an era where energy bills remain high and carbon emissions keep rising, it’s alarming that we’re wasting clean, cheap, abundant energy on a daily basis. As our analysis suggests, this problem is getting worse, not better.

“Billions of pounds have been earmarked to upgrade the transmission network, but we think there’s a better route here than overspending on this one approach to upgrading the electricity system. More efficient use of established technologies, such as battery storage, would dramatically reduce curtailment costs and network investment needs. It would also reduce the need for expensive, complex and disruptive market-based mechanisms such as zonal pricing.

“As well as grid investment increases, battery storage can play a critical role in reducing the cost of managing the energy system and preventing households from paying to waste energy. Storing cleaner energy, to then use it when and where it’s needed the most, will help us run our grid more efficiently and more cheaply - helping us bolster the UK’s energy security and achieve a net zero power sector by 2035.

“What we need now is the National Energy System Operator, Ofgem and the Government quickly getting behind and prioritising the innovative ideas that have been proposed by the industry.”

Field was founded in 2021 to develop, build and operate the renewable energy infrastructure needed to reach net zero and has initially focused on grid-scale battery storage. The company’s first battery storage site in Oldham (20 MWh) commenced operation in 2022 and has already started providing services to the grid. On its own, the Oldham site can provide enough electricity to power 69% of Oldham households for one hour if called on to do so.

Field has a further 410 MWh of battery sites in or preparing to enter construction, and has over 4.5 GWh of projects in development or in exclusivity with partners. The company is also actively developing opportunities for battery storage in Italy, Spain and Germany.