Renewable Energy in Scotland - Hydro-electric Power

Hydro-electric Power

Scotland has 85% of the UK's hydro-electric energy resource, much of it developed by the North of Scotland Hydro-Electric Board in the 1950s. The "Hydro Board", which brought "power from the glens", was a nationalised industry at the time although it was privatised in 1989 and is now part of Scottish and Southern Energy plc.

Numerous remote straths were flooded by these schemes, many of the largest of which involved tunneling through mountains as well as damming rivers. Emma Wood, the author of a study of these pioneers wrote:

I heard about drowned farms and hamlets, the ruination of the salmon-fishing and how Inverness might be washed away if the dams failed inland. I was told about the huge veins of crystal they found when they were tunnelling deep under the mountains.

Current capacity is 1.33 GW and includes major developments such as the 120 MW Breadalbane scheme and the 245 MW Tummel system. Several of Scotland's hydro-electric plants were built to power the aluminium smelting industry. These were built in several "schemes" of linked stations, each covering a catchment area, whereby the same water may generate power several times as it descends.

It is estimated that as much as another 1.2 GW of capacity remains available to exploit, mostly in the form of micro and small-hydro developments such as the existing one in Knoydart and a system planned for Kingussie. In reality, environmental constraints and given that the most easily available catchment areas have already been exploited it is unlikely that the full 1.2 GW will exploited. There is also further potential for new pump storage schemes (at present used to meet peak demand) that would work with intermittent sources of power such as wind and wave. Examples include the 440 MW Cruachan Dam and 300 MW Falls of Foyers schemes. The 100 MW Glendoe Project which opened in 2009 was the first large scale scheme in Scotland for almost fifty years but is likely to be one of the last of its kind. A 2011 report calculated that pumped storage hydro capacity could supply 2.8 GW of electricity for 5 hours, then drop to 1.1 GW and run out of water in 22 hours. The report concluded that even with projected new schemes at Loch Ness and Loch Sloy, pumped storage would not be able to replace wind electricity during extended windless periods.