Invinity flow batteries selected for nine 400 MWh-plus UK storage bids

Vanadium flow battery manufacturer Invinity Energy Systems has been selected by nine UK developers for project bids submitted into the UK government’s new long-duration energy storage (LDES) cap-and-floor support scheme. Each of the proposals is for a system with a capacity of 400 MWh or more.

The announcement indicates the potential on offer for the UK’s new support mechanism to drive investment and take-up of alterantive storage technologies outside of batteries and hydro power, and in this case, flow battery technology.

A statement from the trade body Flow Batteries Europe said the inclusion of multiple large-scale flow battery projects demonstrates that the revenue certainty drives market confidence.

“Since this LDES scheme was first launched, the Invinity team has been engaging closely with numerous developers to submit high quality bids ahead of the deadline,” said Jonathan Marren, Chief Executive Officer at Invinity. “We are delighted with the positive feedback that we have received from our partners, with significant quantities of our UK made vanadium flow batteries being proposed for this important scheme as a result. Should these bids be successful, we believe the build out of our ENDURIUM batteries across the country will not only help to lower energy costs for consumers but also help to provide wider economic benefits across the UK as we scale our operations.”

The company didn’t indicate which developers or stakeholders were part of the nine project bids.

The news comes after Great Britain’s energy regulator, Ofgem, confirmed that 171 applications were submitted into the first LDES auction window. The scheme is designed to de-risk investment by providing a revenue floor for assets that can discharge for eight hours or more, with flow batteries assessed under its “stream 2” category for less mature technologies with a minimum size of 50 MW.

Flow Batteries Europe said this is further evidence that European policymakers must introduce similar revenue support mechanisms to build more long-duration storage. The trade body noted that without such schemes to accelerate deployment, Europe will continue to face significant costs from renewable energy curtailment.

Ofgem is currently consulting on the final financial framework for the scheme and expects to approve the first projects in the second quarter of 2026.