UK’s biggest battery storage project gets underway, using 198MWh of Tesla Megapacks

By Alice Grundy
September 9, 2021
LinkedIn
Twitter
Reddit
Facebook
Email
Construction follows the completion of the 34MW/68MWh Contego battery energy storage facility (pictured). Image: Harmony Energy

Work has started at a battery storage site lauded as the largest of its kind under construction in the UK by developers Harmony Energy and Fotowatio Renewable Ventures (FRV).

The 99MW/198MWh Clay Tye site – which is located near the M25 motorway road in Essex, southeast England – uses Tesla Megapack lithium-ion battery storage system technology as well as Tesla’s Autobidder AI software for real-time trading and control.

It comes after FRV and Harmony Energy recently completed their joint 34MW/68MWh Contego battery energy storage facility near Burgess Hill in West Sussex, England, which went live with a system of 28 Tesla Megapacks and the Autobidder software.

Contego is the second joint project in the UK to use Tesla Megapacks, with the other being the Holes Bay project, also developed by FRV and Harmony Energy in 2020.

This article requires Premium SubscriptionBasic (FREE) Subscription

Enjoy 12 months of exclusive analysis

Not ready to commit yet?
  • Regular insight and analysis of the industry’s biggest developments
  • In-depth interviews with the industry’s leading figures
  • Annual digital subscription to the PV Tech Power journal
  • Discounts on Solar Media’s portfolio of events, in-person and virtual

Or continue reading this article for free

Both sites are to be connected to UK Power Networks’s distribution network, offering the ability to store energy and increase the flexibility of the national grid.

Harmony Energy currently has around 1.2GWh of battery projects construction ready in the UK, and recently sold the development rights for 50MW of battery storage to SSE, with the project expected to come to financial close and be fully constructed over the next 18 months.

Meanwhile, FRV-X, the technology platform of FRV, which in turn is owned by Saudi Arabian industry group Abdul Latif Jameel, has a pipeline of around 1GWh of battery storage projects in different phases of development across the globe, including 83MWh already under operation. 

“The start-up of Contego plant and the progress in the construction of the Clay Tye holds enormous significance for FRV, as it brings us closer to our goal of expanding our portfolio of energy storage projects internationally,” said David Menéndez, head of FRV-X.

Other large-scale battery storage assets in the UK include Zenobe Energy’s 100MW project in Capenhurst, Chester, which it is claiming to be Europe’s largest grid-connected battery, as well as the Minety battery storage site which is made up of two 50MW battery systems with planning permission in place for a third and a 100MW battery storage facility in Ireland developed by Lumcloon Energy and South Korea’s Hanwha Group.

This story first appeared on Solar Power Portal.

Energy-Storage.news is hosting a webinar next week which will explore the role of battery storage and renewable energy in the UK’s drive to net zero, together with EDF.  ‘How the UK grid will handle the growth of renewables and battery storage on the road to net zero,’  takes place on Thursday 16 September at 3pm UK time. See here to sign up.

Read Next

October 22, 2025
South Australia has officially opened its inaugural Firm Energy Reliability Mechanism (FERM) tender round, seeking up to 700MW of long-duration energy storage (LDES) capacity to enhance grid reliability and support the state’s renewable energy transition.
October 14, 2025
IPP Eolian has closed a US$463 million financing package to support the continued construction of Padua 2 and Padua 3, two battery energy storage systems (BESS) totalling 350MW/1.7GWh in Bexar County, Texas.
October 13, 2025
Australia’s most powerful BESS, the 850MW Waratah Super Battery, achieved its first full discharge to the NEM last week.
October 9, 2025
Battery energy storage revenues in Australia’s National Electricity Market (NEM) fell 61% in September 2025 to AU$85,000/MW (US$56,712/MW) as price volatility eased across the grid, according to new research from Modo Energy.
October 6, 2025
Nightpeak Energy has announced commercial operations of its 150MW/300MWh Bocanova Power battery energy storage system (BESS) in Brazoria County, Texas, US.

Most Popular

Email Newsletter