Terra Firma Energy – 1 October 2025

Ofgem has advanced 77 large-scale battery and hydro storage projects to the final stage of its new government-backed “super battery” programme, aimed at cutting wasted renewable power and unlocking billions in green investment.

The Long Duration Electricity Storage (LDES) scheme will enable surplus wind and solar power to be stored for use when demand is high, the wind isn’t blowing, or the sun has set. It’s the first major initiative on long-duration energy storage in over 40 years and a vital part of Britain’s transition to clean power.

From 171 Applications to 77 Projects

When the scheme opened in April, 171 projects applied. Ofgem has now confirmed 77 are eligible to move forward, covering a range of technologies including lithium-ion and flow batteries, as well as pumped hydro systems that use stored water to generate electricity on demand.

Cap-and-Floor Support Model

The programme uses a cap-and-floor model (already proven for electricity interconnectors).

• Projects are guaranteed a minimum level of revenue (the “floor”) if market earnings fall short.
• If profits exceed a set “cap,” the excess is returned to consumers.

This approach provides confidence for investors while protecting billpayers.

Why It Matters

• Cuts waste: Stores renewable power instead of paying wind farms to switch off when supply is high.
• Strengthens security: Provides backup during blackouts and supports grid stability.
• Reduces costs: Uses stored, low-cost solar and wind energy instead of relying on fossil fuel markets.

“Renewable power is the key to seizing control of our own energy system so we don’t want to see a single watt go to waste. That’s why we need to boost our ability to store as much homegrown energy as we can.”
— Beatrice Filkin, Ofgem Director of Major Projects Infrastructure

The Road Ahead

Currently, the UK has 2.8GW of pumped storage across four sites in Scotland and Wales, but very limited long-duration capacity elsewhere. Ofgem will now request detailed project information, with final decisions expected in summer 2026.

Energy Minister Michael Shanks called the programme “a huge step forward in reversing four decades of underinvestment in storage”, highlighting its role in ending reliance on costly fossil fuel markets.