6 minute read
An eco approach
Ido Sella, CEO and Co-Founder, ECOncrete, Israel, describes how ecological engineering can be leveraged to ensure the sustainability of offshore wind.
It has never been more widely recognised that the global climate crisis requires urgent action.
This was highlighted by the recent COP26 event in Glasgow, Scotland, where climate pledges were agreed to keep the world’s rising temperatures to within 1.8˚C of pre-industrialised levels. The most significant part of these pledges was the commitment from global governments to cut carbon emissions, to become net zero and slash the worrying global heating predictions. So, where do we go from here?
To start, it is acknowledged that there clearly needs to be a fundamental shift away from traditional, carbon-emitting energy production, towards clean sustainable energy, while still meeting the demand of an increasingly technologically
developed planet and growing population. Therefore, renewable energy resources such as hydropower, geothermal, solar, wind, and wave energy have become even more popular.
Offshore wind is a rapidly maturing renewable energy technology that is poised to play an important role in future energy systems. With the first offshore wind farm erected in 1991 off the coast of the town of Vindeby on the Danish island of Lolland, European countries such as Denmark, Germany, and the UK have taken the lead for years in the technology’s development.
However, the efficiency of offshore wind has meant that the industry has already seen significant expansion over recent years, with the market growing nearly 30% per year between 2010 and 2018, benefitting from rapid technology improvements and
approximately 150 new offshore wind projects are in active development around the world. The technology opens up sites with high wind resources. Sites can be built quickly, at gigawatt scale, close to key markets, making offshore wind an important addition to the technology portfolio to costeffectively decarbonise the energy sector. Furthermore, this goes alongside increasingly sophisticated development of the infrastructure, with turbines growing in size and in terms of the power capacity they can provide, which in turn is delivering major performance and cost improvements for offshore wind farms.
In 2018, offshore wind provided a tiny fraction of global electricity supply. However, it is clear that it is set to expand strongly in the coming decades into a US$1 trillion business.
Environmental considerations
Those across the environmental advocacy space are strong supporters of offshore wind due to the energy’s systems strong carbon credentials.
However, despite offshore wind being a positive development in the race towards net zero, due attention needs to be given in order to limit the potential disruption to marine habitats and ocean ecosystems.
This is because offshore wind turbines require massive concrete foundations to anchor them in place, at depths of up to 60 m. Substrate degradation and changes to hydrodynamic flow regimes due to poorly designed foundations can lead to local ecosystem destruction and the proliferation of invasive and nuisance species. This can be significantly damaging to marine life, not only on general biodiversity but also on local fishing industries. If offshore wind energy is to be truly sustainable in the long run, the use of ecological materials and nature-inspired design should become the standard.
Floating wind farms
In response to the potential environmental issues caused by traditional offshore wind farms, many have marvelled at the potential for floating wind farms. Whilst most offshore wind turbines are anchored to the ocean floor on fixed foundations, limiting them to depths of approximately 165 ft, floating turbines are tethered to the seabed by mooring lines. These enormous structures are assembled on land and pulled out to sea by boats. Such turbines enable wider possibilities for offshore wind to be utilised in deeper waters, as they are not limited by water depth.
Although the novel anchoring technologies utilise less cement than traditional gravity anchors and clump weights, remote deep-sea wind farms demand much more cable to be laid on the fragile seabed and more substations to be erected. Furthermore, the required tethering creates numerous artificial surfaces that may support invasive species and ecological disruption.
In addition, although floating wind farms do not require the same surface area of concrete as classic base structures, the concrete avoided is expected to be utilised many-fold by complex maintenance and protection requirements. For example, extensive scour protection for numerous cable current-abrasion prop-ups, as well as mounds and anchors will be required. Jacking up cable intersections using grout bags, foundation grouting, and repair clamp grouting will all require vast amounts of cement.
Thus, it is clear that neither approach adequately addresses the environmental issues.
If the offshore wind industry is to expand in this way, seas will become more crowded with turbines, the seabed will be razed, food webs will be destroyed, blue carbon stores will be squandered, and foraging and flight paths will be disrupted. Species extinction is a real risk if the world does not adopt an approach to planning, consenting, and grid development that prioritises zero carbon power and nature recovery over other uses of the sea.
Figure 1. ECOncrete’s ecological concrete solutions are designed to improve the environmental and structural performance of marine projects.
A sustainable approach
In light of such issues, forward-thinking engineers and regulators continue to work hard to re-evaluate how concrete and steel are being used in marine environments, both at the structural and chemical levels. By seriously addressing the way marine flora and fauna interact with the foundations’ surfaces, they aim to cultivate the growth of strong ecosystems from day one. At the leading
edge of ecological engineering are positive feedback solutions created between concrete that enhances biological processes, which in turn protect and strengthen the concrete itself.
By incorporating ecological concrete, instead of ordinary concrete, for all anchoring and maintenance procedures, the renewables industry can significantly reduce its overall environmental impact.
ECOncrete is a pioneering start-up delivering highperformance ecological concrete technologies. With solutions which can be applied to any concrete marine infrastructure, such as breakwaters, ports, and offshore structures, to increase strength and durability whilst transforming it into the base for a thriving marine ecosystem and active carbon sink.
The company has already provided its technology to a range of coastal projects across the globe. For instance, in 2021 ECOncrete provided solutions to stabilise shorelines at the Port of Vigo, Spain, and the Port of San Diego, US.
Furthermore, the company has also been developing its technology to fit offshore infrastructure, as exemplified by its recent partnership with LafargeHolcim in the US, where both companies joined forces to design and produce an ecologically beneficial concrete scour protection unit for offshore wind turbine foundations.
The protection developed by this partnership was the first and currently only structural solution to address the ecological impacts of offshore wind turbines on the marine environment, enabling a more sustainable industry and healthier oceans.
The goal will be to design and manufacture a fullystructural concrete scour protection unit that facilitates the growth of marine organisms, whilst meeting all industry standards for stabilising the seabed. The R&D collaboration includes a large scale pilot project to evaluate the ecological performance of the innovative units in an offshore environment before implementation in full scale installations.
Conclusion
Overall, renewable energies are key players with regard to world energy supply security and the reduction of fossil fuel dependency. As governments across the globe shift their energy production away from carbon-emitting energies, it is clear that the offshore wind industry will grow exponentially. With offshore wind farms requiring long-lived concrete base structures, nature-inclusive design must become the new paradigm.
Whilst there is no one definitive way to calculate the costs of wind and other renewable energy sources, it is important to look at the return on investment over time and determine how they fit into a company’s overall sustainability goals and infrastructure.
By using ecological concrete, carbon footprint penalties will be avoided, stable marine ecosystems can be established, and maintenance costs due to sea current erosion (scouring) can be reduced.
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