Ofgem's Window 1 Provisional Portfolio
Ofgem has officially announced its provisional Window 1 cap-and-floor portfolio, a landmark initiative for the UK's energy transition. The portfolio includes 16 diverse projects spanning pumped hydro, lithium-ion, compressed-air, and vanadium-flow technologies. Collectively, these projects represent a massive 7.6 GW and 137 GWh of storage capacity. The final regulatory decision is expected in autumn 2026, but the provisional selections have already sent ripples through the industry.
Invinity's Strategic Reassessment
Invinity Energy Systems, a prominent player in vanadium-flow batteries, proposed 21 eligible projects representing approximately 16.7 GWh of potential demand. However, only its 520MWh Frontier Legacy project was provisionally selected by Ofgem. In response, CEO Jonathan Marren revealed that the company is actively reconsidering its UK manufacturing and investment plans. Marren indicated that Invinity must now decide whether to pivot and focus more heavily on lucrative opportunities in the US and European markets.
Invinity previously secured a £25 million public equity investment in 2024 from the UK Infrastructure Bank specifically to expand its Scottish manufacturing footprint, making this provisional outcome a significant strategic hurdle.
Regulatory Assessment Criteria
Ofgem’s Multi-Criteria Assessment combines rigorous cost assessment, system modelling, and strategic economic evaluations. While the regulator acknowledges technology diversity and domestic supply-chain development as vital non-monetised benefits, it explicitly noted that diversity is not pursued 'at all costs'. This pragmatic approach has forced manufacturers like Invinity to adapt their global strategies in response to the UK's evolving long-duration energy storage landscape.
This article was assisted by AI analysis. Please refer to the original source for official information.