Scottish energy production boosted by £200m hydro scheme

Installation plans for a 300MW pumped-storage hydroelectricity (PSH) scheme in Scotland were announced today (24 August), in the same week that the Scottish Energy Minister claimed that the sector was "at a crossroads" and required substantial UK Government support.

The £200m PSH electricity storage facility on the Isle of Lewis will significantly increase (from 40% to 80%) the use of the Western Isles cable being installed by the National Grid to export and import electricity generated from renewable energy sources on the islands.

Generating enough electricity to power more than 200,000 homes, the innovative Eishken Limited-operated scheme will utilise the sea as the lower reservoir from which water will be pumped uphill to a second reservoir at a higher reservoir. Eishken expects that this method will create a much lower environmental impact than would be caused by creating a second reservoir.

The company’s owner Nick Oppenheim said: “There are very few PSH schemes throughout the UK and what we are proposing is particularly innovative given the use of the sea as the lower reservoir. 

“This scheme will not only materially enhance the benefits to be derived from the Western Isles link but will make a material difference in the supply of energy to the mainland. It will also be a key element in the Scotland’s renewable energy armoury.”

The project forms part of the already consented 162MW Muaitheabhal Wind Farm on the Isle of Lewis, and will share any financial surplus with the local community following a three to five-year construction period.

Investment risk

The news comes two days after Scotland’s Business, Innovation and Energy Minister Paul Wheelhouse highlighted the importance of a collaboration between UK Government and its Scottish counterpart to secure the future of the hydropower industry.

Wheelhouse suggested that PHS could play a crucial role in Scotland’s energy system, and called for closer working between the two Governments on extending pumped energy storage capacity.

Visiting a pumped hydro storage plant at Foyers, near Loch Ness, Wheelhouse said: “The hydro sector is at a crossroads, with a number of exciting developments opening, but with some future investments, especially in small scale hydro, at risk due to changes in subsidies, brought in by the UKG, putting jobs at risk in many rural communities.

“Pumped hydro storage – like the facility I have seen today in Foyers – is a case in point. As well as being able to further support peak demand, expanded pumped hydro storage would also be able to effectively store greater levels of electricity at times when renewable energy output is high but demand is low.

“However, this part of the hydropower industry requires substantial government support – not the kind of extra hurdles that changes in subsidies from the UK Government have put in place.”

‘Coherent storage strategy’

Scotland has often been viewed as a “prime candidate” to accelerate the UK integration of energy storage due to its rich heritage in hydropower. Indeed, Scotland’s hydropower sector has thrived in recent years, with the Scottish Affairs Committee recently revealing that the UK is sourcing 85% of hydro capacity from the country. 

Despite the reported potential for a grid-scale electricity storage system to decarbonise the UK’s electricity by £3.5bn, concerns remain over the UK Government’s lack of clarity over support for valuable ‘smart-grid’ technologies.

Speaking in response to the call from Scotland’s Energy Minister for increased UK pumped hydro support, the Renewable Energy Association’s (REA) senior policy analyst Frank Gordon commented: “While the REA is not calling for any direct subsidies for new energy storage projects in the UK, we wholeheartedly back the SNP’s recent call for a coherent UK-wide energy storage strategy.

“There is a multitude of new storage technologies now available, including new pumped hydro projects in Scotland and Wales, that need to be supported by Government. The anticipated dramatic growth in energy storage is poised to reduce system costs, improve system stability, and significantly modernise our electricity sector.”

George Ogleby

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