Mainstream and Maple Power partner for Celtic Sea floating wind tender




29 November 2022



3 Floatinf Offshore Wind turbines

Mainstream and Maple Power bring floating wind expertise, offshore development experience and financial strength to the Celtic Sea tendering process ,in a partnership that will be focused on the development of a UK supply chain

Maple Power, a leading European offshore wind developer, and Mainstream Renewable Power are jointly exploring the upcoming Celtic Sea Floating Offshore Wind Tender in the UK, which will be launched in 2023.

The Crown Estate is advancing the Celtic Sea seabed leasing tender for floating wind, which is anticipated to deliver a total of 4 GW of renewable energy by 2035. The region has the potential to generate up to an additional 20 GW by 2045, helping to support the UK’s energy transition and future energy security.

Crown Estate seabed options map off the coast of Wales

The Crown Estate has been narrowing down seabed options in the Celtic Sea that will be able to support an anticipated 4 GW of floating wind capacity by 2035

Together, Maple Power and Mainstream bring a combination of deep sector knowledge, extensive development experience and financial strength to target commercial-scale floating projects. The combined expertise of Maple Power and Mainstream will contribute to UK supply chain development, industry leading innovation and benefit renewable energy growth in a key market.

Since 2019, Maple Power, together with its partners and shareholders, has co-developed over 2 GW of offshore wind projects across Europe, including Provence Grand Large, the first non-recourse project financed floating offshore wind project currently in construction.

Mainstream has an extensive offshore wind development track record in the UK, having developed and consented 20% of the UK’s offshore wind capacity either in operation or under construction, through Hornsea One (1.2 GW), Hornsea 2 (1.4 GW) and Neart na Gaoithe (450 MW).

Through its recent combination with Aker Offshore Wind, Mainstream has taken an early mover position in floating wind and, together with its partners, is currently developing gigawatt scale projects in South Korea (1.2 GW) and Scotland (1.8 GW). Mainstream is also a major shareholder of the leading floating wind technology provider, Principle Power.

Tove Røskaft, Head of Offshore Wind at Mainstream, said:

The Celtic Sea can play a leading role in reaching the UK’s net zero ambitions, while providing renewable energy for green value chains in Wales and beyond through its proximity to key industry. I believe Mainstream and Maple Power bring together highly complementary capabilities and experience which will support us well in our aim to bid on and develop floating offshore wind in the region.

Maple CEO Michael van der Heijden and Tove Røskaft Head of Offshore Wind at Mainstream

Maple CEO Michael van der Heijden and Tove Røskaft, Head of Offshore Wind at Mainstream, highlight the complementary capabilities of floating wind partners


Michael van der Heijden, Chief Executive Officer at Maple Power, said:

Maple Power has been active in floating offshore wind since 2019, when the team started to co-develop the Provence Grand Large project in France. With construction of that project now well underway, I am keen for Maple Power to further deploy its floating offshore wind expertise. Combined with Mainstream’s track record, the two companies together are therefore well-placed to consider opportunities in the Celtic Sea tender.

The Celtic Sea is defined as the waters in the region around the South Wales coast and the Southwest peninsula within the United Kingdom, covering an area of 300,000 km2.

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