The UK regulator Ofgem has given approval to 77 projects entering the final stage of assessment under the ‘superbattery’ support scheme. The programme has been developed by the government to secure investment, encourage growth and curb green energy waste.
Long Duration Energy Storage (LDES) plays a key role in expanding the UK’s grid by storing additional renewable energy when weather conditions produce more than needed.
Innovations in grid infrastructure and LDES are changing the way renewable energy is managed. Unlike fossil fuels, solar and wind energy are intermittent – there are times when more energy is produced than is needed and times when it is not available. LDES projects are designed to meet this challenge.
In support of the Government’s pledge to build major new LDES projects for the first time in 40 years, Ofgem launched a new support scheme in April to unlock billions in investment and boost the UK’s tech economy.
An initial group of 171 projects applied to take part in the scheme. 77 eligible projects reached the second phase. These include a variety of storage methods – lithium-ion (Li-Ion) batteries, flow batteries and pumped storage hydro .
The UK currently has 4 PV plants (2.8 GW) in Scotland and Wales. These operate as natural batteries – electricity is stored by pumping water into a mountain and released when needed – and are already critical to the electricity system. In parallel, other LDES technologies are being developed – liquid air energy storage (LAES), compressed air energy storage (CAES), and liquid batteries.
Background
In October 2024, the Government introduced an LDES investment support scheme, which is administered by Ofgem. The cap and floor scheme received widespread support in the public consultation and follows the model successfully applied to electricity interconnectors.
In April 2025, Ofgem opened the first application window and checked projects for eligibility against a clear set of published criteria to ensure a fair and transparent process for all.
The regulator now requires approved projects to submit more detailed bids for final assessment. In the summer of 2026 it will become clear which of these will receive investment support under the Cap and Floor scheme.
„Cap and Floor is a regulatory scheme to be used to support these projects:
- Cap: The cap is a quid pro quo arrangement that sets a maximum revenue and sees projects pay money to consumers if they end up making more than is considered a fair rate of return on invested capital.
- Floor: This is the minimum revenue provided to the project. If the project’s revenue falls below this floor, consumers pay the LDES operator the difference up to the floor level.
Being awarded a cap and floor means the project is underwritten to provide financial protection on the downside. It ensures that the project can earn a minimum income to recover their investment. If revenue is high, consumers are rewarded with the excess revenue being shared with consumers.
