Europe’s biggest battery storage project, between Inverness and Aberdeen, is now commercially operative, and able to cut electricity bills by improving grid efficiency.

By absorbing excess wind power the Zenobe plant will avoid the need for turbines being paid to switch off.

The first phase of the project at Blackhillock can store enough power to supply 200 megawatts of electricity for two hours. Expansion to 300 megawatts by next year will enable it to supply 3.1 million homes – more than every household in Scotland – for one hour.

The grid does not yet have sufficient capacity to safely transport power to the south of the UK, resulting in the wind farms being paid millions of pounds to switch off and gas plants making up the shortfall.

In order to match supply and demand, the National Grid has to move electricity from where it is being made to big population centres, mainly in England. Until new cables come into operations there aren’t to do that.

This bottleneck means that when it is very windy there is too much electricity for these cables to handle without risking damage.

Zenobe said the north of Scotland project would “significantly reduce the amount of wasted clean energy” and estimates that it will lower consumer bills by more than £170 million over 15 years. The first phase increases the capacity of operational battery storage in Scotland by more than 30%.

James Basden, Zenobe’s co-founder, said: “It soaks up the power from the wind farms when there is too much power and releases it when it’s needed, according to the capacity on the grid.”

Zenobe is co-owned by KKR, the American private equity firm, and Infracapital, the infrastructure investment arm of M&G.

The Blackhillock site cost in the region of £150 million to £200m and Zenobe is building another 300-megawatt battery near Kilmarnock. A 400-megawatt site at Eccles in the Scottish borders is also planned.

“In the period of three to four years we will be committing £1 billion into Scotland to build these batteries,” said Mr Basden.

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