Norwegian green power giant Statkraft has bought a 450MW 'water battery' project next to Loch Ness in Scotland to store renewable energy.

Statkraft, which already operates a portfolio of onshore wind farms in Scotland, has bought the planned pumped-hydro project from Intelligent Land Investments Group (ILI).

The project, located next to the lake that is the legendary home of the Loch Ness monster, 14km south-west of Inverness, is pending a final investment decision

Pumped storage plants act like giant water batteries by using reversible turbines to pump water from a lower reservoir to an upper reservoir which stores excess power from sources such as wind farms when supply outstrips demand.

The turbines are then reversed to bring the stored water back through the plant to generate power when it is needed.

“Statkraft is fully committed to supporting the UK in strengthening its energy security and helping to secure the economic benefits of the net zero transition,” said the company’s UK managing director Kevin O’Donovan. “The acquisition of this significant pumped hydro storage scheme will play a key role in that.”

“But there needs to be an appropriate support mechanism in place,” he added, “so we’re now looking to the UK Government to provide the certainty that will allow us to proceed with confidence.”

O’Donovan was echoing calls from industry and the Scottish government for Westminster to support the development of long duration energy storage – including pumped hydro storage – through a market support mechanism.

Industry has called for a “cap-and-floor mechanism” that ensures a minimum level of revenue for such projects. This would kick-start the construction of various pumped hydro projects that have already secured planning permission.

ILI CEO Mark Wilson also urged the UK government to “provide the support mechanisms now for long duration storage and strive to become a world leader in achieving net-zero.”

In July, the Scottish government gave the go-ahead for a 600MW pumped hydro plant on Ben Cruachan, or the “Hollow Mountain” as it is often known.

The developer of that project, the UK’s Drax Group, also called for a financial stabilisation mechanism to support such batteries.