Storage, Wind Power

Scottish Power Mulls Doubling Size of Hydro Energy-Storage Plant

Scottish Power Ltd. may double the size of a hydro plant that stores energy by pumping water up to a mountain reservoir when supply of power exceeds demand as it boosts reliance on volatile renewable generation.

Scottish Power, owned by Spain’s Iberdrola SA, is studying the possibility of expanding the 440-megawatt Cruachan facility near Oban in southwest Scotland, Simon McMillan, a spokesman, said by phone. There’s no timeframe for the study, he said.

“Pumped storage was originally built in the late 1950s and early 1960s to take the excess production from the nuclear fleet and it’s becoming more attractive now because of the increasing amounts of renewables on the system in Scotland,” McMillan said. “We’re going to have excess production that’s more than demand at night, in particular, and the most viable way of storing that electricity is through pumped storage.”

The need to store energy at times of low demand for use when consumption rises is becoming increasingly important as more economies shift to using intermittent and unpredictable sources of power from the sun and wind. Scotland is seeking to get all of its electricity from renewable sources by 2020.

The Cruachan facility would store surplus power from nearby clean energy plants. It’s too early to put a price on a possible expansion or how long it would take to construct, McMillan said.

Pumped storage facilities use power from the grid at times of low demand to pump water up hills to a reservoir. When demand is high the water is released, turning turbines to generate electricity. The U.K. now has four pumped storage plants.

While the system has been used in power generation for more than a century, it’s limited to mountainous areas and has been criticized for harming wildlife habitats. SSE Plc in December won Scottish approval to build a 600-megawatt hydropower plant.

Scottish Power and DONG Energy also announced that the Duddon Sands Offshore Windfarm off the coast of England has started the commissioning process, with 42 of its 108 turbines installed. The 389-MW project is expected to be completed later this year. 

Copyright 2014 Bloomberg

Lead image: Hydropower via Shutterstock