The Capenhurst battery, located near Merseyside, is also reported to be the first in the world to have a commercial contract to provide reactive power services, to help ensure that system voltages remain within a pre-determined range. According to Zenobē, this will offer ‘large cost savings for consumers as gas plants will not need to run as frequently and fees won’t have to be paid to curtail wind power when the network becomes congested’.

In December 2022, the National Grid paid £82mn to wind farm operators to turn their turbines off in efforts to stop the UK energy system from becoming overwhelmed, says Zenobē. It claims that over the first 15 years of operation the battery at Capenhurst will save around £58mn on curtailment costs that would have previously been passed on to consumers, while also preventing some 1mn tonnes of CO₂ from entering the atmosphere.

Traditionally, reactive power services have been provided by local fossil fuel power stations. However, as the world transitions to net zero new sources of reactive power need to be found. ‘Capenhurst coming online will significantly lower the region’s reliance on gas imports to secure the grid. This creates greater energy security and lowers the risk of blackouts for a more efficient electricity grid. The battery will also ease network constraints by importing electricity at times of peak renewable generation,’ Zenobē says.

In other news, Zenobē reports that it has reached financial close and begun construction of the first 200 MW of a 300 MW battery site in Blackhillock, Scotland. Located between Aberdeen and Inverness, ‘the project will be the first in the world to deliver a full suite of active and reactive power services using a transmission-connected battery, representing an important milestone in the UK’s net zero transition’, states the company, and will take over Capenhurst’s position as Europe’s largest grid-connected battery.

Phase 1 of the project (200 MW) is due to go live in summer 2024 with Phase 2 (an additional 100 MW) due to go live in 2H2026.

Zenobē claims that, over 15 years, the project ‘will avoid around 2.3mn tonnes of CO₂ from entering the atmosphere and lower consumer bills by over £170mn’.

UK’s largest virtual power plant
Meanwhile, Octopus Energy, the UK’s third largest energy supplier, reports that it now manages over 100 MW of electric vehicle (EV) charging power via its smart tariff ‘Intelligent Octopus’ – more than the largest battery on the grid.

Intelligent Octopus is the UK’s first 100% flexible car charging tariff, providing cheap, clean electricity for 10p/kWh, allowing an average driver to charge their EV for less than a third of what it would cost to charge up on a standard variable tariff, reducing fuel costs to about 3p/mile, claims the company. The cars on the tariff hold enough energy to power a city the size of Leicester for an hour, it adds.

Customers use an app to set the time and amount they want their vehicle charged by. Octopus Energy’s Kraken energy technology platform then works in the background to automatically charge the cars up when there is abundant, low-cost energy and when the grid is less busy, helping to balance out demand and supply on the grid.

Alex Schoch, Head of Flexibility at Octopus Energy, comments: ‘We urgently need to build flexible grid technology to turbocharge the green energy system. The tariff acts as a virtual power plant, shifting demand out of peak times and therefore cutting bills for everyone.’

Intelligent Octopus launched in 2022 as a specialist tariff for managing smart tech solutions. As well as across the UK, it is live in Texas, US, where it optimises customers’ smart thermostats and forms the control mechanism for the company’s latest initiative, the Zero Bills home.