Headquartered in Dublin, Ireland, Mainstream has an extensive presence across Europe.

Mainstream is currently developing floating offshore wind at its Arven Offshore Wind Farm in Scotland and actively seeking offshore wind development opportunities in Norway, and Sweden, and exploring further opportunities across continental Europe.

We have offices in Dublin, Edinburgh and Oslo.

Offshore leadership team

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Tove Røskaft

Head of Offshore Wind

Aidan Guinan

Chief Financial Officer, Offshore

Geir Olav Berg

Chief Technology Officer, Offshore

Sebastian Bringsværd

Senior Vice President Offshore Wind Norway

Sian Lloyd Rees

UK Managing Director

Holger Matthiesen

SVP Offshore Wind Europe and Global New Markets

Tove Røskaft

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Tove Røskaft

Head of Offshore Wind

Tove was appointed Head of Offshore Wind in 2022 and holds responsibility for the Offshore Wind center of excellence including development, projects, partnerships and technology.

Her appointment follows the integration of Aker Offshore Wind where she held the role of Chief Operating Officer. Tove joined Aker Offshore Wind in 2021 and has extensive global leadership experience. Her previous leadership experience at Aker includes roles such as Executive Vice President, Country Manager, Chief Communication Officer as well as leading large transformation projects in Aker Solutions.

In addition, she has held several other leadership roles within project management, manufacturing, and engineering. Through her over 25 years of experience in the energy industry, Ms. Røskaft has demonstrated the ability to inspire and motivate teams to deliver high performance and results.

Ms. Røskaft holds a M.Sc. in Marine Hydrodynamics from NTNU, the Norwegian University of Science and Technology.

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Aidan Guinan

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Aidan Guinan

Chief Financial Officer, Offshore

Aidan Guinan was appointed to the role of Chief Financial Officer, Offshore in March 2023 having led the merger and integration of Aker Offshore Wind into Mainstream in 2022.

Aidan has held several positions in Mainstream since he joined in 2014 most recently as Group Head of Investment Risk, Legal and Governance where he was responsible for reviewing new investment opportunities, assessing capital allocation and diversification of risk across the group. Prior to that Aidan was Group Head of Commercial supporting the regions in commercial and project finance transactions and Project Director where he led the disposal of Mainstream’s Neart na Gaoithe 450 MW offshore wind project to EDF in 2018.

Prior to joining Mainstream, Aidan worked for an Irish infrastructure developer where he led numerous M&A transactions and raised over US $1.25bn of project finance debt for two toll road PPP transactions in Ireland. Aidan trained with PwC Ireland and is a Fellow of the Institute of Chartered Accountants in Ireland.

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Geir Olav Berg

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Geir Olav Berg

Chief Technology Officer, Offshore

Geir Olav Berg is responsible for engineering and technology at the Mainstream Renewable Power Offshore Platform. He has over 30 years of experience in the offshore industry including Engineering Manager for Aker Solutions floating wind department. Geir Olav has held several management positions within subsea technology and project management at various Aker Solutions companies. Geir Olav has a passion for the opportunities presented renewables in combination with offshore technology. He holds a MSc in Marine Technology from the Norwegian University of Science and Technology (NTNU) with specialization in Naval Architecture, Cybernetics and Robotics.

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Sebastian Bringsværd

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Sebastian Bringsværd

Senior Vice President Offshore Wind Norway

Sebastian Bringsværd heads up the Norway region in Mainstream and is responsible for developing the Norwegian market, including our two bids for floating offshore wind at Utsira Nord and bottom-fixed offshore wind at Sørlige Nordsjø II.

Previously, Mr. Bringsværd worked at Equinor, where he was a member of the senior management team and where he built up the New Energy Division over the course of six years. In his previous position, he was responsible for establishing and heading up the floating wind unit which covered commercialization, deployment, and industrialization of floating wind in existing and new markets. He has held many leadership roles throughout his career and joined Aker Offshore Wind in November 2022. Mr. Bringsværd holds an MBA from Lancaster University, UK, and a law degree from the University of Oslo, Norway.

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Sian Lloyd Rees

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Sian Lloyd Rees

UK Managing Director

In a career spanning over 30 years Sian has extensive business experience as a Senior Leader in both Energy and IT industries, having held several leadership roles in both blue chip and start-up Companies.

Since starting her career in the Halliburton Corporation focused on North Sea and Africa, Sian has held senior positions in Oracle Corporation managing a global accounts division, was the UK MD of Aker Solutions Ltd and is currently the UK Managing Director of Mainstream Renewable Power, an Aker Company and a floating wind developer. She considers that building on the capability, solutions, and industrial heritage in the UK from oil and gas will support the scale and pace needed to deliver affordable clean energy from offshore floating wind.

Sian sits on the Boards of Serica Energy plc, Offshore Energy UK (OEUK) as co-chair and participates in other industry boards. She is also the industry Supply Chain Champion, on behalf of the UK Government and OEUK, supporting delivery of the £16billion North Sea Transition Deal.

Holger Matthiesen

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Holger Matthiesen

SVP Offshore Wind Europe and Global New Markets

Holger is in his position since 2021 and has responsibility for MRPs offshore wind development activities in Europe (outside Norway, UK and Ireland) and selected global markets.

Previous career steps included Offshore wind development and construction projects in Europe and Oil and gas exploration and production activities globally.

Holger is a trained geologist with a French engineering degree and an executive MBA. He is engaged in several non-executive board positions in industry associations.

We are fully focused on expiditing our ambitious growth plans and leveraging our collective expertise and resources to transform Mainstream into a global renewable energy major this decade.

Mary Quaney - Group Chief Executive Officer

CONTACT US

Dublin Office

Ground Floor, Block G,
Central Park,
Carmanhall and Leopardstown,
Dublin 18, D18 NH10.

[email protected]

+353(1)2902000

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Emmet Curley

Head of Communications and Positioning