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Conventional Hydro

Glendoe Hydroelectric Scheme

Above Fort Augustus, Inverness-shire — discharges into Loch Ness

Glendoe is Scotland's newest large-scale conventional hydroelectric scheme, completed in 2009. A single 100 MW Pelton wheel turbine uses a 600 m head of water from Loch Tarff, with an 8 km tunnel running through the mountain to Loch Ness. A Pelton wheel is used (rather than a Fra…

Operational · Since 2009
100 MW
Installed Capacity
1
Turbines
180 GWh
Est. Annual Output
2009
Commissioned

📋 Project Overview

Glendoe is Scotland's newest large-scale conventional hydroelectric scheme, completed in 2009. A single 100 MW Pelton wheel turbine uses a 600 m head of water from Loch Tarff, with an 8 km tunnel running through the mountain to Loch Ness. A Pelton wheel is used (rather than a Francis turbine) due to the very high head — jets of water strike curved cups on the wheel. The project suffered a major tunnel collapse in 2009 but was restored and returned to operation.

Site Schematic

UPPER RES. LOWER RES. PENSTOCK TAILRACE GEN. GRID HEAD: 600m · POWER: 100 MW · 1 turbines

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

Key Facts

Scotland's most recently built large-scale conventional hydro scheme
Uses a Pelton wheel (high-head design) — unusual in the UK
600 m head of water — equivalent to twice the height of the Eiffel Tower
8 km pressure tunnel bored through granite bedrock
Tunnel collapse in 2009 required full inspection and repair — took 3 years
The intake valve is visible at Loch Tarff from a minor road

🔧 Technical Specifications

Capacity (MW)100 MW
No. of turbines/units1
Turbine / unit modelPelton wheel, single 100 MW unit
Unit capacity100 MW each
Head (hydro)600 m
Upper reservoirLoch Tarff (14 million m³, at 590m elevation)
Lower reservoirLoch Ness (at 16m elevation)
Tunnel / penstock8 km pressure tunnel through the mountain
Annual output180 GWh/year

🔌 Grid Connection & Infrastructure

🏢 Development & Ownership

DeveloperSSE Renewables
Owner / operatorSSE Renewables
Year consented2005
Construction started2006
Commissioned / target2009
Capex estimate~£150 million
LocationAbove Fort Augustus, Inverness-shire — discharges into Loch Ness
RegionScotland
Coordinates57.14°N, 4.47°W

📅 Project Timeline

2005
Planning consent granted
2006
Tunnelling begins using tunnel boring machine
Jun 2009
Commissioned — then immediately offline due to tunnel collapse
2012
Returned to full operation after tunnel repair

🌿 Environmental & Planning

Located above Loch Ness — part of the Great Glen. Loch Tarff and connecting streams support brown trout. A compensation flow is maintained in the diverted watercourse. The intake on Loch Tarff is screened to prevent fish entrainment.