Scottish and Southern Energy’s £800m vision for hydro dam in Great Glen

The company’s green energy division, SSE Renewables, has submitted a planning application to the Scottish Government to construct a 600-megawatt power scheme above Loch Lochy, with depths of 230ft the third deepest loch in Scotland. Under the plans for the new “pumped storage” hydro-electric scheme, a 300ft high dam would be built at Coire Glas, in the hills above the freshwater loch, creating a new reservoir in the glen.

During periods of low demand for power, electricity would be used to pump water from Loch Lochy to the upper reservoir. The water would then be released to create energy at a time of peak demand.

The company, however, has warned no final decision on the massive hydro scheme would be made before 2014 at the earliest and would be dependent on a “satisfactory regulatory framework”, including a change in the current transmission charging regime.

The proposed £800 million development at the western end of the Great Glen, near Spean Bridge, north of Fort William, was welcomed yesterday by Scotland’s renewable energy sector. A spokesman for Scottish Renewables said the project would strengthen Scotland’s portfolio of renewable energy sources.

He said: “Hydro-electricity has the quickest reaction time of any generation technology, whether that is renewable energy or traditional fossil-fuel generation. Pump storage is going to be crucial for balancing demand.”

A spokeswoman for SSE said the scheme would help meet peak demand and would be capable of extracting and storing up to 30 gigawatt hours of electricity, releasing energy to and from the electricity transmission system to help balance supply and demand for power at a national scale.

She said: “The scheme would be the largest hydro project to be built in Scotland and the first brand new pumped storage scheme to be developed in Great Britain since work began on the Dinorwig scheme in Wales in 1974.

“With a cost currently estimated at £800m it would also be one of the largest construction projects in Scotland.”

However, she added: “If the project receives consent, a final investment decision is unlikely to be taken before 2014 at the earliest, and progress of this scheme – and other similar developments – will be dependent upon a satisfactory public policy and regulatory framework, including a change in transmission charging regime.”

But environmental and hillwalkers’ organisations voiced concerns about the scheme.

Dave Morris, the director of Ramblers Scotland, branded the project a “white elephant”. He said: “There is little chance that the public funds will be found to build such an massive dam in an important wild land area.

“The future for wind farm development is offshore, especially off the east coast of England.

“A Loch Lochy hydro scheme would be in the wrong place, too far away from the offshore wind farms and, with little future for onshore wind farm development, as public subsidies for such development are slashed, there would be no use for the Loch Lochy scheme.

“I am surprised that SSE did not wait until 1 April [April Fools’ Day] to make this announcement.”

Helen McDade, the head of policy with the conservation body the John Muir Trust, also voiced concerns about the massive scheme. She said: “The John Muir Trust would need to see very good evidence that this scheme is justified for the country in that it would significantly improve the UK energy security of supply in the most cost-effective way. That economic case needs to be made even before the environmental impacts are considered.

“The impact on wild land will be very considerable and the John Muir Trust and others would need re-assured that the environmental impacts are justified. There is little evidence that the regulator, Ofgem, or the Department of Energy and Climate Change have done that work. Indeed, Ofgem is still consulting on aspects of this so the application is premature.”

SSE has set up a dedicated webpage as part of the consultation process.

According to the energy giant, the scheme will require the construction of a new dam and upper reservoir at Coire Glas above Loch Lochy.

A powerhouse complex would be constructed in an underground cavern, together with a series of tunnels to provide access and convey water between Loch Lochy and the new upper reservoir. An administration building and jetty would also be built on the shores of Loch Lochy.

The company said: “Once completed the scheme would have minimal visual impact in the Great Glen. It is envisaged that the construction period would last up to five years, with an average workforce of around 150 throughout this time.

“The Coire Glas Pumped Storage scheme would be unique when compared to other existing pumped storage schemes in the United Kingdom in its ability to extract and release energy to or from the electricity transmission system for a much longer period.

“It is estimated that this would be in the region of 50 hours continuous pumping or release which is far greater than the capacity of existing pumped storage schemes in the UK.”

SSE estimates that , following construction, there will be a surplus of approximately 450,000 cubic metres of excavated rock which will have to be disposed of somewhere.

Possible solutions include using some of the rock for constructing the dam and other infrastructure projects, or transporting the surplus material by barge to Fort William.

The area earmarked for the tunnel outlet is also in the vicinity of existing forestry roads which are incorporated in the Great Glen Way – a long distance route for walkers between Fort William and Inverness.

Two Munros, mountains over 3,000ft, are also in the area – Meall na Teanga (hill of the tongue) and Sron a Choire Ghairbh (rough corrie peak).

SSE said: “Where appropriate for safety, it is proposed to provide a new path to run parallel to the existing track to separate walkers and cyclists from the works, constructed to the same standard as the existing Great Glen Way. This path would be constructed at commencement of works and it is proposed that this would remain in place as a permanent diversion to this section of the Great Glen Way.”

The Great Glen is a series of glens running 100km from Inverness to Fort William.

• THE first successful public hydro-electricity scheme in Scotland was constructed in 1890 to power the Benedictine Abbey in Fort Augustus, at the west end of Loch Ness, and supply 800 village homes.

Hydro electricity is produced using the power of running water to turn turbines in power stations. The technology dates to the late 19th century when private hydro stations were built to smelt aluminium. It was another 40 years before the first large-scale scheme came in 1930 at Rannoch and Tummel Bridge in Perthshire.

Scottish Hydro Electric, then the North of Scotland Hydro Electric Board and now part of the Scottish and Southern Energy Group, was established by an Act of Parliament in 1943.

SSE is now the UK’s largest hydro generator, with 1,450 megawatts of capacity including 300MW of pumped storage, or more than 65 per cent of UK capacity. SSE recently built the 100MW Glendoe station, at Loch Ness – the first large hydro station built in 50 years.