Posted on June 6, 2022
Denmark-based energy company Ørsted has developed a technique to support coral reefs by growing corals on offshore wind turbine foundations, and plans to run a proof-of-concept trial in Taiwan in June.
Ørsted noted that coral reefs provide habitat for an estimated 32% of all marine species and benefit 1 billion people worldwide, directly or indirectly, according to figures from the UN Environment Programme. However, climate change is increasing sea surface temperatures, which can create a bleaching effect that threatens the survival of tropical coral reef ecosystems, adding to the global biodiversity crisis.
Climate change is becoming the biggest driver of biodiversity loss, and the expansion of offshore wind could be central to efforts to provide renewable energy and reduce carbon emissions. Many governments are planning a significant build-out of green energy infrastructure at sea, and Ørsted believes that if done right, the expansion of offshore wind energy needed to fight climate change can also integrate solutions that support and enhance ocean biodiversity.
In June 2021, the company set a goal to deliver a net-positive biodiversity impact from all new renewable energy projects it commissions from 2030 at the latest.
The ‘ReCoral by Ørsted’ project, which began development in 2018, is an example of company exploring how to achieve this. The 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.
Coral bleaching can be caused by increased surface temperatures in shallow waters. However, at offshore wind farm locations further offshore, vertical mixing in the water column prevents extreme temperature increases which results in more stable temperatures.
The idea behind the ReCoral project is that the relatively stable water temperatures at offshore wind farm locations will limit the risk of coral bleaching, allowing 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 from Ørsted teamed up with private and academic coral experts to mature and test the concept. In 2021, the ReCoral team successfully grew juvenile corals for the first time on underwater steel and concrete substrates at a quayside test facility.
An offshore proof-of-concept trial, which will begin in June, will attempt to settle larvae and grow healthy corals at the Greater Changhua 1 offshore wind farm, which is co-owned by Ørsted (50%) and is located 35-60km off the coast of Taiwan. The trial will test the concept in open waters on 1m2 areas on four separate wind turbine foundations.
Mads Nipper, group president and CEO of Ørsted, said: “To halt climate change and create a sustainable future for the planet, its ecosystems, and its people, we must speed up the transition from fossil fuels to renewables. 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.”
He added: “If we succeed with ReCoral and the concept proves to be scalable, this Ørsted innovation could create a significant positive impact on ocean biodiversity.”
Ørsted is collaborating with the Penghu Marine Biology Research Center in Taiwan. Together, they have developed a non-invasive methodology for coral seeding, in vitro fertilisation, larvae transport, and larvae attachment to wind turbine foundations. Instead of removing anything from existing coral ecosystems, the non-invasive approach developed by ReCoral relies on the collection of surplus coral egg bundles that wash up on shorelines and would not otherwise survive.
Hern-Yi Hsieh, director of Penghu Marine Biology Research Center, said: “We’re excited to take part in such a great initiative and partner up with the world’s most significant player in offshore wind.
“Environmental protection and marine biodiversity will continue to be one of the key topics of the world in the coming decade. It’s great to see that, apart from its effort to supply clean energy, Ørsted is also launching its coral project here in Taiwan to promote environmental friendliness. We’re honoured to participate in the project, and we look forward to more such initiatives in the future.”
If the proof-of-concept trial at the Greater Changhua offshore wind farms is successful, Ørsted plans to explore opportunities for scaling up the initiative. The ultimate aim will be to use additional coral larvae generated at offshore wind farm locations to restore and enhance threatened near-shore reef systems.
Ørsted noted that the ReCoral concept could be applied to offshore foundations of any kind in tropical waters around the world. The company plans to share the results along with the techniques the ReCoral team develops with the broader coral conservation community, as well as with other wind farm developers. Ørsted expects that the findings will be useful regardless of whether the ReCoral pilot succeeds.