Reengineered energy

By repurposing an abandoned open-cast mine into a pumped storage giant, we are rewriting the industrial legacy of Scotland.

Rewriting the industrial legacy of Scotland

From coal mine to grid backbone

Glenmuckloch takes a site shaped by Scotland’s industrial past and retools it for the energy system we need for the future. Using a closed-loop hydro electric design, the project will transform a former open-cast coal mine into a long-duration energy storage facility, strengthening security of energy supply and helping integrate more renewable generation across the UK.

Image Credit: Tony Marsh Photography

Scale

Store it. Move it. Use it.

A typical 50MW, two‑hour battery stores around 100MWh. Glenmuckloch is designed to store around 1,700MWh, equivalent to around 17 of these battery projects.

210MW

Generating capacity

Two 105MW reversible hydro‑turbines will deliver flexible power when the grid needs it. Built to turn stored energy into rapid, dependable output again and again. A reengineered legacy asset, designed for long‑duration system value.

8+ hours

At full output

Long‑duration storage designed to cover the moments renewables can’t. This is why pumped storage matters: it balances the system over sustained periods, not just minutes. Stability isn’t optional in a renewable grid, it’s engineered.

Closed‑loop

Pumped storage scheme

Water is cycled between reservoirs, storing energy as gravity, then releasing it as power. Designed to support deliverability. A continuous system built to perfect the cycle, not consume it.

Image Credit: Extreme E

Built for balance

Stores excess renewables

Captures surplus electricity during high renewable output and stores it for later use.

Releases power fast

Delivers flexible output to support stability when demand rises or renewable generation falls.

Reduces curtailment costs

Absorbs surplus generation, reducing waste and system cost.

Why Pumped Storage