The Gwynt Glas floating offshore wind project in the Celtic Sea has announced that Sumitomo Corporation is joining the development as an equal partner, restructuring the joint venture into a three-way split with each partner holding a 33.33% stake.

The announcement, made on 10 August 2026, sees the Japanese integrated trading and business investment company take its place alongside EDF power solutions UK and Ireland and ESB, while DP Energy continues to provide development support focused on early stage project delivery and local engagement.

A Restructured Joint Venture

The addition of Sumitomo Corearly-stagerks a significant evolution in the governance and composition of the Gwynt Glas project. Previously a joint venture between EDF power solutions UK and Ireland and ESB, the project now operates under an equal three-way ownership structure.

DP Energy's role remains intact, with the company continuing to offer expertise in project development and community engagement, though it does not hold an equity stake in the restructured partnership.

Matthieu Hue, CEO of EDF power solutions UK and Ireland, described the new arrangement as a strengthening of the project's capabilities. "Their extensive global experience in offshore wind development and investment complements our own and ESB's, creating a powerful partnership dedicated to delivering this vital project for Wales and the UK," he said.

Jim Dollard, Executive Director of Generation Trading at ESB, added that the development represents a milestone for ESB's broader strategic goals, describing offshore wind as a cornerstone of the organisation's net zero carbon emissions strategy.

About the Gwynt Glas Project

Gwynt Glas is a proposed floating offshore net-zero located in the Celtic Sea, with a generating capacity of up to 1.5 gigawatts. The project is described by its developers as innovative in its use of floating wind technology, a sector that is still in relatively early stages of commercial-scale deployment compared to traditional fixed-foundation offshore wind.

The project has been making progress through the planning process, with the development team confirming that a Scoping Report was successfully submitted to the Planning Inspectorate during the summer of 2026.

The Scoping Report submission is a formal step in the development consent order process under the UK's nationally significant infrastructure project framework, and its completion signals continued forward momentum for the project as it advances toward later development phases.

The project's stated aims include delivering clean, domestically sourced energy for Wales and the United Kingdom, contributing to broader national energy security objectives and supporting economic growth in the region.

Sumitomo's Strategic Rationale

For Sumitomo Corporation, the investment in Gwynt Glas represents part of a wider strategic commitment to the United Kingdom energy market. Jun Minase, General Manager of the Overseas Energy Solutions SBU at Sumitomo Corporation, said the project offers an important opportunity to contribute to the energy transition.

"The United Kingdom remains an important strategic market for Sumitomo Corporation. Through this investment, we aim to contribute to the UK Government's Net Zero 2050 ambitions while supporting the energy transition and the realization of a more sustainable society," he said.

Sumitomo Corporation is listed on the Tokyo Stock Exchange under ticker 8053 and operates as an integrated trading and business investment company with offices in more than 60 countries and regions.

The Sumitomo Corporation Group comprises approximately 500 companies and around 80,000 employees on a consolidated basis. Its business activities span ten groups, including an Energy Transformation Business division, which aligns with its growing involvement in renewable energy development internationally.

The Partners Behind the Project

EDF power solutions UK and Ireland is a subsidiary of EDF Group, which describes itself as one of the world's largest low carbon electricity companies. The UK and Ireland arm currently operates a portfolio of 50 renewable energy sites, including battery storage, onshore wind and offshore wind assets.

The company has stated plans to reach 10 gigawatts of capacity across wind, battery and solar projects by 2035, with assets spread across various stages of planning, development and construction.

ESB, the Irish state utility, was established in 1927 under the Electricity Supply Act and remains majority owned by the Irish Government, which holds a 97.7% stake.

The remaining 2.3% is held by the trustees of an Employee Share Ownership Plan. ESB operates across the full electricity value chain, from generation through transmission and distribution to customer supply, and also uses its network infrastructure to carry fibre for telecommunications purposes.

DP Energy, which continues to play a development support role on Gwynt Glas, brings experience in early stage renewable energy project delivery and stakeholder engagement at a local level, according to the announcement.

Floating Wind in the Celtic Sea

The Celtic Sea has become an area of increasing focus for floating offshore wind development in the United Kingdom, given its significant wind resource and water depths that make fixed-foundation turbines impractical.

Projects such as Gwynt Glas are seen as part of a broader industrial ambition to commercialise floating wind technology at scale, which would open up deeper water sites that cannot be developed using conventional offshore wind methods.

The partnership now in place on Gwynt Glas brings together organisations with backgrounds spanning European utility development, Irish state energy infrastructure and Japanese global trading and investment operations, reflecting the cross-border nature of large-scale offshore wind investment in the current market.

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