Nestled in a deep valley in Argyll, the glistening hydroelectric dam at Ben Cruachan is not only a beautiful piece of engineering. For 51 years it has served as a key piece of Britain’s infrastructure, churning out electricity to meet peaks in UK demand. These days it is being used more than ever, says Hugh Finlay, generation director at ScottishPower, its owner, who is leading an expansion plan costing as much as £600 million. With Britain increasingly reliant on intermittent wind and solar power, the UK’s ageing pumped storage plants are enjoying a revival. Cruachan’s turbine hall, located within a granite cavern 400 metres below the mountainside, hums with activity 24 hours a day. “It’s never been used as much as now,” Mr Finlay, behind a bank of screens, says. “The more wind and solar that is built in the UK, the more we need it.” Cruachan and a similar scheme at Dinorwig in Snowdonia play an increasingly important role helping to balance the UK grid. During the first three months of this year, 25.1 per cent of Britain’s electricity came from renewables such as wind. That is up from 22.8 per cent a year ago and less than 5 per cent in 2005. Since supplies of renewable power are volatile, there is a growing need for ways to store that energy for when it is wanted. “In a world of intermittent generation you really need storage,” Neil Clitheroe, global retail director for Iberdrola, ScottishPower’s Spanish parent, says. That’s why, if it can win government support, ScottishPower wants to expand Cruachan’s capacity from 440 megawatts to 1,040 megawatts. It will submit a planning application this autumn. The UK’s total pumped storage capacity is 2,800MW, with Scottish plants at Cruachan and Foyers, and Welsh schemes at Ffestiniog and Dinorwig. At least double that level is needed to provide enough storage to cope with the amount of wind being developed. Other projects are also being considered that could boost the UK’s overall pumped storage capacity to 4,400MW. SSE plans to build an £800 million plant at Coire Glas in the Great Glen that could generate 600MW, while the Duke of Buccleuch is planning to build another in a disused quarry in Dumfriesshire.
Times 4th July 2016 read more »