Yesterday marked a milestone in the construction of Scotland's largest hydro- electric power scheme for half a century, when a giant boring machine completed a five-mile tunnel through the mountains above Loch Ness at Glendoe.

When completed, the Scottish & Southern Energy plant will collect rainwater from the mountains and channel it through vast turbines before allowing the water to drain into Loch Ness itself. As energy projects go, the cost is relatively modest – £140 million – yet it will provide clean, renewable electricity sufficient to light the homes of a city the size of Glasgow.

The question arises: why not more hydro power? It is a proven technology in which Scotland had led since the 1950s. Unlike many other forms of renewable energy, hydro power can be pumped into the UK national grid at the flip of a switch: when operational next year, the Glendoe plant will be able to start generating at full capacity in only 30 seconds. Above all, hydro power is cheap in an era when oil costs $100 a barrel.

Scottish & Southern estimates that the operating cost of producing electricity from Glendoe will be a tenth of that of a conventional gas or coal-fired station. However, there are drawbacks to installing further hydro power, at least of the traditional model. Public opinion will no longer allow the damning of glens to create the water pressure necessary to drive the turbines. An alternative technology – drawing water from fast-flowing Highland rivers – runs the risk of draining those rivers dry. An infamous case in point is the River Garry, a tributary of the Tay, which is denuded of water for a 13-mile stretch as a result of an earlier hydro scheme. Local people are attempting to use the new EU Water Framework Directive to get Scottish & Southern to remedy the damage – a demand the company should take to heart.


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