Turning more of the UK鈥檚 mountains into massive 鈥渨ater batteries鈥� could substantially reduce the need for new nuclear power stations and save the country hundreds of millions of pounds, researchers have estimated.
New pumped hydro projects, which use off-peak electricity to pump water uphill and release it later to generate electricity, could save the UK energy system between 拢44 million and 拢690 million a year by 2050, according to a report by a team at Imperial College London. The exact figure hinges on how much of the storage technology is built as the UK rapidly increases its reliance on variable wind and solar power.
Most of the savings stem from having to invest in fewer new power stations, followed by fewer new pylons and a reduction in the costs National Grid bears to balance electricity supply and demand.
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Burning question
The study says that by storing cheap wind power in this way and dispatching it at times of need, each 1000 megawatts of pumped hydro could replace 750 MW of nuclear power, or a gas plant fitted with carbon capture.
鈥淭here is massive variation in wind power 鈥� this is where this long duration storage comes in,鈥� says Goran Strbac, who modelled the savings. In a statement, the Scottish government welcomed the report and said it showed 鈥渢he value of pumped hydro storage in a net-zero power system鈥�.
Whether the UK needs new nuclear to reach its carbon goals is a burning question. The government is up financial support for a 拢20 billion nuclear power station in Suffolk that could be built by French energy firm EDF and which would have a capacity of 3200 MW.
Net zero
The Imperial College London research was commissioned by UK-based energy firm SSE, which last October won planning permission for a pumped hydro scheme up to 1500 MW. But the company says energy market policies aren鈥檛 yet in place to give enough certainty for it to raise the nearly 拢1.5 billion needed to build the in the Great Glen between Inverness and Fort William, Scotland. Almost all the UK鈥檚 existing are in Scotland and Wales.
鈥淭he challenge for the Coire Glas investment case is although revenue streams are there, they are highly uncertain and short term in nature,鈥� says Mike Seaton at SSE. He wants to make a final investment decision by the end of 2023, so construction could start the following year with the scheme operating before 2030. If built, it would be the first new pumped hydro project in the UK for more than 30 years.
The UK government it will lay out how it plans to remove barriers to such long-duration storage in spring 2021. 鈥淓lectricity storage, including pumped hydro storage, has a key role to play in helping us achieve net-zero emissions,鈥� says a spokesperson for the Department for Business, Energy and Industrial Strategy.
