Mainstream Renewable Power nets €575m investment from Mitsui

24 Mar 2022

Image: © Rafa Irusta/

Mitsui will take a 27.5pc equity stake in Mainstream Renewable Power, while Aker Horizons will hold a 54.4pc stake.

Irish wind and solar energy company Mainstream Renewable Power has received a €575m investment from Japanese conglomerate Mitsui.

The announcement comes just over a year after renewable energy investment company Aker Horizons agreed to acquire a 75pc stake in Mainstream. The deal valued the Dublin-based company at €1bn.

Mitsui’s investment now values Mainstream at €2.1bn. The investment will come in the form of new common shares, corresponding to a 27.5pc equity stake in the company, and the deal is expected to close next month.

Mitsui will take an active part in helping Mainstream achieve its long-term growth goals alongside Aker Horizons, which will retain a 54.4pc stake following the closure of the deal.

Mainstream was founded in 2008 by Irish energy entrepreneur Eddie O’Connor, who still retains a minority interest in the company.

The latest investment is intended to help accelerate the company’s expansion into other markets, spur its growth in green ammonia and green hydrogen production, and increase its construction and operations capacity across multi-gigawatt platforms.

Its will aid Mainstream’s routes to market, particularly in terms of corporate power purchase agreements, and help it expand across the Americas, AfricaAsia-Pacific and Europe.

Mary Quaney, group chief executive of Mainstream, said that the company is delighted to welcome Mitsui as its new strategic partner alongside Aker Horizons. “Together we are fully focused on expediting our ambitious growth plans and leveraging our collective expertise and resources to transform Mainstream into a global renewable energy major this decade.”

Kazumasa Nakai, Mitsui’s COO, added: “We are convinced that the participation in Mainstream will further strengthen the strategic partnership between the Aker group and Mitsui, driving forward our renewable energy transition and greenhouse gas reduction in response to global climate change.”

Kristian Røkke, CEO of Aker Horizons and chairperson of Mainstream, noted that Mitsui’s “rich industrial heritage, global presence and like-minded approach to sustainability” would bring “substantial value” to Mainstream.

Since Aker Horizons’ acquisition last year, Mainstream has increased its global portfolio by 5.2GW, bringing the pipeline to 16.6GW. It also has approximately 8GW of identified opportunities, bringing the total volume of pipeline and opportunities to 25GW.

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Blathnaid O’Dea was a Careers reporter at Silicon Republic until 2024.