A Biologist Shares 2 Environmental Benefits Of Offshore ‘Mega-Windmills’
Other research has shown that underwater noise levels generated from pile-driving can cause significant hearing damage to marine mammals in construction area, with large whales being particularly….
A Biologist Shares 2 Environmental Benefits Of Offshore ‘Mega-Windmills’
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(Another Hired “Mega-Windmills” Piece About Environmental benefits.)
A recent study suggests that increasing the size of offshore wind turbines yields multifold gains. ... [+]GETTY
New research published in Scientific Reports suggests that, when it comes to improving the offshore wind industry’s environmental footprint, building bigger turbines may be the wave of the future.
The authors, led by Naveed Akhtar of the Institute of Coastal Systems in Germany, show that replacing five megawatt turbines with larger, 15 megawatt structures in Europe’s North Sea increases overall efficiency while reducing some of the environmentally disruptive effects. Here are two ways that bigger wind turbines promote better ecological outcomes, according to the research.
1. Bigger Turbines Mean That Less Have To Be Built
The researchers conducted a sophisticated simulation of offshore wind power in Europe’s North Sea region under two competing scenarios: one in which 5 megawatt structures were spaced at intervals of 0.6 kilometers and another in which 15 megawatt structures were spaced at 1.8 kilometer intervals. The larger rotor diameter of the “mega-windmills,” approximately twice the size of the 5 megawatt structures, means that less have to be built in a given area to produce an equivalent amount of energy.
According to their simulation, an overall energy capacity of 108 gigawatts was achieved with a third of the individual wind turbines using the larger, 15 megawatt structures.
Constructing offshore wind turbines can have a variety of environmental costs, thus wind farms with ... [+]GETTY
“Larger turbines have greater rotor diameters, allowing them to capture more wind and generate more electricity,” state the researchers. “Additionally, taller turbines can produce more energy due to the faster and more consistent winds found at higher altitudes, resulting in a more stable and reliable source of energy. They can also continue to operate at lower wind speeds, increasing the number of hours they can generate electricity.”
From an environmental standpoint, fewer wind turbines in a given area–even if they are twice the size–equates to a less destructive development phase. For one, less raw materials are needed to construct the wind farms. Second, fewer windmills in a given area means that less pile-driving needs to occur to affix the turbines to the seabed. Other research has shown that underwater noise levels generated from pile-driving can cause significant hearing damage to marine mammals in the construction area, with large whales being particularly sensitive to the low frequency sound produced from pile-driving.
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Moreover, it is reasonable to expect that vessel traffic during the construction phase would be reduced if only a third of the windmills needed to be constructed. This is important, as decreased vessel traffic means fewer potential collisions with marine mammals.
2. Bigger Turbines Are Less Atmospherically Disruptive
The researchers also show, through their simulations, that larger wind turbines spaced at wider intervals would likely have a smaller effect on local climate conditions–which is another important environmental consideration. Other research suggests that changes to the local climate, produced by windmills’ wakes, can include an increase in temperature and humidity downwind of the wind farm site.
“The impact on near-surface winds and heat flux is slightly less with fewer and larger wind turbines compared to many smaller wind turbines,” state the researchers. “This could mean that larger wind turbines have less impact on the ocean dynamics and ecosystem, as sea surface winds and heat fluxes are important drivers of these systems.”
Given this information, the researchers suggest that the European Union explores the possibility of replacing its 5 megawatt turbines in the North Sea with larger models.
“Overall, deploying 15 megawatt turbines in offshore wind farms may offer advantages for ocean dynamics and marine ecosystems, supporting the European Union’s carbon neutral objectives,” conclude the authors.
The European Union aims for carbon neutrality by 2050. Offshore wind energy is poised to play a pivotal role in this transition.
This article does not paint a true picture and is therefore misleading. The inference is that fewer turbines means fewer pilings, so there is less effect on sea life. The article fails to mention that the piles for each of the larger turbines will necessarily be much more robust and/or numerous, likely resulting in greater direct damage to ocean life from infrasound and shock waves during turbine construction. Also; the article fails to mention infrasound production by the turbines when they are in operation. Larger turbines produce more powerful and lower frequency infrasound than smaller turbines. Lower frequencies are more problematic and dangerous. Unlike the effects of infrasound and shockwaves during construction, the effects of infrasound during operation are never ending. The prognosis is that the overall damage from larger turbines may be much greater than from more numerous smaller turbines. More study is needed, so any attempt at definitive answers is premature.