Pumped storage hydro plants enjoy dual boost

There was good news for the hydroelectric industry on both sides of the Atlantic this week, after Scottish and Southern Energy (SSE) announced plans for two new pumped storage developments and the US government unveiled $32m (£19.5m) of new funding for the sector.

Announcing its plans at the official opening of its new £160m hydroelectric scheme at Glendoe in Scotland, SSE said it would seek guidance from the Scottish government on proposals to build a 300MW and 600MW pumped storage plant in the Great Glen.

The company said it was aiming to submit planning applications for the two developments in 2011. It added that both projects would require new dams to be built, but insisted the pumping and electricity generation infrastructure would be built underground, limiting the visual impact of the developments.

Pumped storage systems work using two reservoirs that are built at differing heights. During periods of peak demand, energy is generated by releasing water from the upper reservoir to drive turbines. The water is pumped back up to the upper reservoir from the lower reservoir during periods of low energy demand.

The last pumped hydro plant was built in the UK more than 30 years ago at Dinorwig in Wales, but interest in the technology has been revived in recent years as energy firms look for a carbon-free means of plugging any energy shortfalls that result from the intermittent nature of wind power. The approach also allows excess energy produced by wind farms during periods of high winds to be effectively stored, by using the resulting electricity to pump water from the lower to the upper reservoir.

"Our goal is to maintain a diversified portfolio of power stations, with the flexibility to respond to customer demand for electricity, while achieving a 50 per cent reduction in the carbon dioxide intensity of electricity produced," said SSE chief executive Ian Marchant. "Pumped storage can help us achieve this goal and, after 30 years, I believe is a technology whose time can come again."

Meanwhile, on the other side of the Atlantic, energy secretary Steven Chu announced that $32m of economic stimulus funding would be provided to help fund the modernisation of existing US hydroelectric plants.

"There is no one solution to the energy crisis, but hydropower is clearly part of the solution and represents a major opportunity to create more clean energy jobs," said Chu.

The Department of Energy said the funding would be made available to upgrade projects at both large and small-scale hydroelectric plants. It added that Secretary Chu was particularly interested in developing pumped storage technologies that would support solar and wind energy projects by allowing energy to be stored.