"> 🔌 EV Partnership Switch to Octopus Energy & unlock exclusive smart EV charging rates Find out more →
Pumped Storage Hydro

Coire Glas

Great Glen, Inverness-shire — above Loch Lochy, near Spean Bridge

Coire Glas will be the UK's largest energy storage project when built — more than doubling the country's current pumped storage capacity overnight. Located in the Scottish Highlands above Loch Lochy, the 1,500 MW station will store 30 GWh of energy, equivalent to running every …

Consented / Approved · Target 2030
1,500 MW
Installed Capacity
30,000 MWh
Energy Storage
4
Turbines
700 GWh
Est. Annual Output
2030
Target Date

📋 Project Overview

Coire Glas will be the UK's largest energy storage project when built — more than doubling the country's current pumped storage capacity overnight. Located in the Scottish Highlands above Loch Lochy, the 1,500 MW station will store 30 GWh of energy, equivalent to running every current pumped storage station in Britain simultaneously for over a day. It received its Development Consent Order in 2023, but a Final Investment Decision awaits the government's Cap-and-Floor revenue support mechanism.

Site Schematic

UPPER RES. LOWER RES. PENSTOCK TAILRACE GEN. GRID ⇑ PUMP ⇓ GENERATE HEAD: 700m · POWER: 1,500 MW · 4 turbines

Schematic diagram — not to scale. Illustrative layout based on project specifications.

Key Facts

Will more than double the UK's pumped storage capacity at a stroke
30 GWh storage — equivalent to ~1.5 million EV car batteries
Head of 700 m — one of the highest-head PSH projects proposed in UK
New upper reservoir requires a 1.5 km long, 50 m high dam
Key blocker: awaiting Cap-and-Floor revenue support mechanism from DESNZ
Would provide critical long-duration balancing for 70%+ renewable grid

🔧 Technical Specifications

Capacity (MW)1,500 MW
Storage (MWh)30,000 MWh
No. of turbines/units4
Turbine / unit modelReversible Francis pump-turbines (supplier TBC)
Unit capacity375 MW each
Head (hydro)700 m
Upper reservoirNew raised Coire Glas reservoir (1.5 km dam, 50m high)
Lower reservoirLoch Lochy (existing Great Glen loch)
Annual output700 GWh/year

🔌 Grid Connection & Infrastructure

🏢 Development & Ownership

DeveloperSSE Renewables
Owner / operatorSSE Renewables
Year consented2023
Commissioned / target2030
Capex estimate~£1.5 billion estimated
LocationGreat Glen, Inverness-shire — above Loch Lochy, near Spean Bridge
RegionScotland
Coordinates57.13°N, 4.92°W

📅 Project Timeline

2016
Development application submitted to Planning Inspectorate
2023
Development Consent Order granted by Secretary of State
2024
Cap-and-Floor mechanism consultation by DESNZ
2025/26
Final Investment Decision expected if mechanism confirmed
2030
Target for commercial operation (7+ years construction)

🌿 Environmental & Planning

The Great Glen is a major wildlife corridor. The upper reservoir is in a remote corrie — visible impact limited. Key environmental concerns: red deer management, impact on upland peat, views from the Caledonian Canal. The site is not within a National Park or National Scenic Area.