UK LDES Cap & Floor to Open in April

Technical Decision Document published by Ofgem ahead of first application window opening.

Wednesday 12 March 2025

Invinity Energy Systems welcomes the release of a Technical Decision Document (“TDD”) by Ofgem, confirming key final details of the UK LDES Cap & Floor scheme.

The Company is extremely pleased with this development, as it reinforces the critical role long duration storage solutions like Invinity’s could have in a future low-cost, highly reliable UK electric grid.

As anticipated, eligible technologies have been split into two application routes: Stream 1, which will focus on most-mature technologies (specifically Pumped Hydro Storage (“PHS”)), and Stream 2, which will be dedicated to proven, innovative technologies such as flow batteries.

The TDD contains a number of important confirmations which underline the suitability of Invinity’s technology and an appropriate development pathway for the scheme, including:

  • A two-month application window which will open in April 2025;
  • An indicative total capacity of between 2.7 and 7.7 GW;
  • A minimum 8-hour storage duration (increased from 6 hours under the previous guidance);
  • A minimum project size requirement of 400 MWh (increased from 300 MWh under the previous guidance);
  • A 25 year project life target with no degradation of asset performance; and
  • A programme floor that is intended to support returns on all invested capital, including both debt and equity.

The TDD has further confirmed the Company’s expectations regarding eligibility, including the exclusion of projects that can already be deployed without support, and flow batteries being one of only three technologies currently expected to participate within Stream 2.

Finally, the TDD has confirmed that there will be two delivery tracks with entry into service required by 2030 and 2033. The Company expects that its established manufacturing capability in the UK will enhance its ability to delivery as part of the first delivery track, giving it an advantage over solutions with a longer delivery timeline.

With the TDD published, the Company is looking forward to continuing to engage with numerous developers looking to submit bids within the first application window. This news follows the announcement in February that Invinity and Frontier Power have partnered to submit up to 2 GWh of bids into the scheme.

Yesterday’s announcement firmly underlines the importance of longer duration energy storage for the UK’s future energy system. Our vanadium flow batteries, if deployed at the scale envisaged by the LDES cap and floor scheme, will enhance UK energy security while helping to lower costs for consumers and bring a host of wider economic benefits including the creation of new ‘green’ jobs in the UK.

“We are delighted that we continue to engage deeply with the teams at DESNZ and Ofgem in respect of the vital role LDES has to play in the UK’s energy future and look forward to our proven, Made in Britain vanadium flow batteries playing a significant role in the country’s future, clean, low-cost electric grid.

– Jonathan Marren, Chief Executive Officer, Invinity Energy Systems