Invinity Energy Systems PLC (IES), a vanadium flow battery energy storage company, has disclosed that National Wealth Fund Limited increased its voting rights stake to 28.14% on 12 November 2026, up from a previous position of 24.67%. The notification, filed under TR-1 Major Holdings rules and sent to the FCA on 13 November 2026, confirms the acquisition of additional ordinary shares carrying direct voting rights. The move strengthens the UK government-backed fund's position as a significant shareholder in Invinity, a company focused on long-duration energy storage solutions. Investors may be watching this development closely given the scale of the holding and the identity of the investor.

Key Points

  • Invinity Energy Systems PLC (IES) — developer of vanadium flow battery energy storage systems
  • National Wealth Fund Limited raised its stake to 28.14% of voting rights, up from 24.67%
  • The threshold was crossed on 12 November 2026; the total voting rights held now stand at 230,672,017 shares
  • Investors should watch for any further regulatory disclosures or strategic announcements involving the National Wealth Fund's growing position

National Wealth Fund Crosses Major Holding Threshold in Invinity Energy Systems

The TR-1 notification confirms that National Wealth Fund Limited, registered in Leeds, UK, and ultimately controlled by HM Treasury, acquired voting rights in Invinity Energy Systems PLC on 12 November 2026. The acquisition pushed its holding from 24.67%, representing 108,695,652 voting rights, to 28.14%, representing 230,672,017 voting rights. All rights are held directly under DTR5.1, with no financial instruments or indirect holdings reported. The notification was completed and filed on 13 November 2026, in accordance with FCA disclosure requirements under the Disclosure Guidance and Transparency Rules.

Scale of Voting Rights Increase Reflects Significant Additional Share Acquisition by HM Treasury-Backed Body

The jump from 108,695,652 to 230,672,017 voting rights represents a substantial increase in the absolute number of shares held by National Wealth Fund Limited. The announcement states the reason for notification was an acquisition of voting rights, with no financial instruments such as options or convertible instruments involved. The National Wealth Fund is not controlled by any natural person but sits within the HM Treasury chain of control, as confirmed in the disclosure. This positions a UK government-backed institution as the company's largest disclosed shareholder by a considerable margin, based on information available in this announcement.

Invinity Energy Systems' Vanadium Flow Battery Focus Places It at Centre of Long-Duration Storage Sector

Invinity Energy Systems develops and deploys vanadium flow batteries, a technology designed to provide long-duration, grid-scale energy storage. The company operates with ISIN GB00BS9F9D74 and is listed with ticker IES. Long-duration energy storage has attracted growing policy and investment attention in the UK as the electricity grid transitions away from fossil fuels, making Invinity's technology relevant to both commercial and strategic infrastructure objectives. The National Wealth Fund's expanding commitment may reflect alignment with broader UK energy transition investment mandates, though the announcement does not provide explicit commentary on investment rationale.

Regulatory Disclosure Filed Directly with FCA Under Standard Major Holdings Notification Rules

The filing follows standard TR-1 notification procedures, requiring disclosure when a shareholder crosses a notifiable voting rights threshold in a UK-listed issuer. The form was submitted to both Invinity Energy Systems PLC and the FCA on 13 November 2026, one day after the threshold was crossed, meeting the regulatory timeline. The disclosed position carries no attached financial instruments, confirming the holding is entirely in ordinary shares with direct voting rights. No proxy voting arrangements were noted. Investors tracking significant shareholder activity in Invinity will find this disclosure on the FCA's regulatory register.