Study: The benefits of pumped hydro energy storage for UK power supply
S. Himmelstein | April 15, 2021Long-duration energy storage technologies like pumped hydro are expected to play an essential role in decarbonizing electricity supply in the U.K. by integrating renewable energy and maintaining security of supply. A study conducted by Imperial College researchers concludes that just 4.5 GW of new long duration pumped hydro storage with 90 GWh of storage could save up to £690 million per year in energy system costs by 2050.
The analysis focused on the benefits of new long-duration pumped hydro storage in Scotland as the current most established long-duration energy storage technology. SSE Renewables recently received a revised consent from the Scottish government for what would be the U.K.’s largest pumped hydro energy storage scheme – Coire Glas – located near Loch Lochy in the Scottish Highlands. The proposed 1.5 GW scheme would more than double the current amount of pumped hydro storage capacity in the U.K., providing a low carbon resource to help cost-effectively manage the fluctuations of the electricity system.
System savings of 2 GW/200 GWh long duration-pumped hydro energy storage in a system with and without seasonal thermal storage. Source: Imperial College
The main benefit of long duration storage compared to short duration batteries is the ability to continuously charge up the storage with excess renewables and discharge power to the grid for several hours or days when wind and solar output is low.
About 75% of the savings to the energy system realized from projects like Coire Glas would be from the avoided capital expenditure in higher cost electricity generation technologies that would otherwise be needed to meet the national target of carbon neutrality by 2050 while assuring security of supply.