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Ørsted Trials Turning Offshore Wind Turbine Foundations Into Safe Havens For Corals

The first-of-its-kind ReCoral by Ørsted project aims to implement a non-invasive approach for restoring the health of coral reef ecosystems by growing healthy coral colonies on the foundations of offshore wind turbines.

Published 2 years ago | About a 4 minute read

Image: Ørsted/YouTube

Danish sustainable energy company Ørsted is planning a world-first attempt to support coral reefs by growing corals on offshore wind turbine foundations. Together with Taiwanese partners, the company will test the concept in the tropical waters of Taiwan this summer. The goal is to determine whether corals can be successfully grown on offshore wind turbine foundations and to evaluate the potential positive biodiversity impact of scaling up the initiative.

According to the UN Environment Programme, coral reefs provide habitat for an estimated 32 percent of all marine species and benefit 1 billion people worldwide, directly or indirectly. But increased sea temperatures due to climate change and common chemicals in products such as sunscreen are threatening the survival of tropical coral reef ecosystems, adding to the global biodiversity crisis.

Climate change is becoming the biggest driver of biodiversity loss, and a substantial expansion of offshore wind is central to tackling these interlinked crises. Governments are planning a significant build-out of green energy infrastructure at sea; if done right, Ørsted believes the expansion of offshore wind energy needed to fight climate change can also integrate solutions that support and enhance ocean biodiversity.

The ReCoral by Ørsted™ project aims to implement a non-invasive approach for collecting surplus indigenous coral spawn as it washes ashore and for growing healthy coral colonies on the foundations of nearby offshore wind turbines.

The idea

Increased surface temperatures in shallow waters can lead to coral bleaching. At offshore wind farm locations further offshore, temperatures are more stable due to vertical mixing in the water column, preventing extreme temperature increases.

The idea behind ReCoral is that the relatively stable water temperatures at offshore wind farm locations will limit the risk of coral bleaching and allow healthy corals to grow on wind turbine foundations. Corals will be grown close to the water's surface to ensure sufficient sunlight.

In 2020, biologists and marine specialists in Ørsted teamed up with private and academic coral experts to mature and test the concept. In 2021, the ReCoral team successfully grew juvenile corals on underwater steel and concrete substrates at a quayside test facility for the first time. The first trial will begin in June at the Greater Changhua offshore wind farms in Taiwan to test the concept in open waters on four separate wind turbine foundations.

“Governments are preparing a significant expansion of offshore wind energy; and I’m confident that if done right, the offshore wind build-out can support and enhance ocean biodiversity,” says Mads Nipper, Group President and CEO of Ørsted. “If we succeed with ReCoral and the concept proves to be scalable, this Ørsted innovation could create a significant positive impact on ocean biodiversity.”

Working with coral experts

Together with the Penghu Marine Biology Research Center in Taiwan, Ørsted has developed a non-invasive methodology for coral seeding, in vitro fertilization, larvae transport and larvae attachment to wind turbine foundations. Rather than removing anything from existing coral ecosystems, ReCoral’s non-invasive approach relies on the collection of surplus coral-egg bundles that wash up on shorelines and would not otherwise survive.

If the trial is successful, Ørsted will explore opportunities for scaling up the initiative — with the ultimate aim of using additional coral larvae generated at offshore wind farm locations to restore and enhance threatened near-shore reef systems. Scaling the initiative could also be critical in helping Ørsted achieve its ambition to deliver a net-positive impact on biodiversity across all of its new energy projects, from 2030 at the latest.

“We’re excited to take part in such a great initiative and partner up with the world’s most significant player in offshore wind,” says Hern-Yi Hsieh, Director of Penghu Marine Biology Research Center. “Environmental protection and marine biodiversity will continue to be one of the key topics of the world in the coming decade. We’re honored to participate in the project, and we look forward to more such initiatives in the future.”

The ReCoral concept could be applied to offshore foundations of any kind in tropical waters around the world. Ørsted will share learnings and the techniques with the broader coral conservation community and with other wind farm developers, expecting that the findings will be useful regardless of whether the ReCoral pilot succeeds.