With an installed capacity of around 100MW, Glendoe will be Scotland’s first conventional large-scale hydro power station for almost 50 years.

The Prime Minister detonated an explosion beginning development of the tunnels which will allow water from a new reservoir, which will be built over 600m above Loch Ness, to reach an underground power plant near the southeast corner of the loch before being discharged into the loch itself.

Commercial operations are due to commence from the winter of 2008-2009.

SSE said the project has the potential to generate enough power for 250,000 homes, and it is hoped the construction phase could create 400 jobs.