Friday, June 20, 2014

Latest research on environmental impact of wind turbines

Offshore wind farms and noise pollution issue

Although majority wind turbines are built on land there are also many suitable offshore locations where offshore wind turbines can be built. Offshore wind energy projects have lately become very popular in some countries of the world, most notably United Kingdom and offshore wind energy is set to play major role in global clean energy market in years to come. Offshore wind energy projects can provide better efficiency compared to the wind energy projects on land because of powerful winds that are also more stable and frequent as compared to those that blow on land. The major drawback is however construction costs, being significantly higher for offshore wind energy projects since they need to be constructed to withstand extreme weather conditions.

Growth in offshore wind generation is expected to play a major role in fight against climate change issue by meeting carbon reduction targets around the world, however the environmental impact that offshore wind turbines have on marine life hasn't been much researched as is also the case with the impact of construction noise on marine species. There could available be a lot more information about this matter because the scientists from the United Kingdom and the United States have recently managed to develop a method to assess the potential impacts of offshore wind farm construction on marine mammal populations, with the special emphasis on the noise made while driving piles into the seabed which occurs while installing wind turbine foundations.

The researchers report that pile driving during the construction of offshore wind farms produces a staggering amount of noise which is potentially harmful to marine species. This is particularly hazardous for already endangered marine species, such as protected populations of seals, dolphins and whales.

The researchers studied ongoing construction in and around the North Sea, where many proposed wind farm sites are on submerged offshore sandbanks. These sandbanks provide important habitats for many different marine mammals and seabirds. Several previous researches focused their attention on the potential impacts to birds, while this latest comprehensive research tries to assess the potential long-term impact of construction on protected marine mammal populations, particularly harbor seals. In United States where offshore wind power development is set to grow rapidly in years to come, this type of assessment could be applied to wind turbine construction that may impact a number of endangered species, including three whale species: the North Atlantic right whale, the humpback whale, and fin whale.

This study aims to present takes a worst case assessment of the short term impacts of noise pollution coming from installation of offshore wind turbines and how these negative effects of excessive noise may influence longer term population change. The information gathered from this study should provide information that would allow regulators to balance their efforts to meet both climate change targets and existing environmental legislation thus paving the way for sustainable offshore wind energy development.

It has been reported that harbor seals can be impacted by the noise pollution in several different ways. Particularly damaging loud construction activities can cause traumatic hearing injury or even death at the close range while little bit less loud noise pollution levels could lead seals to avoid the area and lose favorite feeding grounds, potentially causing greater competition in other areas thus leading to problems with finding food which could negatively result in lower reproduction or survival rates. Also, the changes in hearing sensitivity could make seals more vulnerable to predation, thus further reducing their numbers and putting their future survival in question.

Bat deaths from wind turbines – Exaggeration or not?

Several different studies were studying the impact that wind turbines have on bat population. There hasn't been a general opinion on this matter with some studies reporting minimal bat dearth rates while other reporting alarming bat death rates.

A brand new estimate of bat deaths caused by wind turbines concludes that more than 600,000 of bats have probably died in 2012 in the United States. This latest estimate is published in an article in Bioscience and has caused plenty of controversies. The researchers   used sophisticated statistical techniques to predict the probable number of bat deaths at wind energy facilities from the number of dead bats found at 21 locations, correcting the statistics for the installed power capacity of the facilities.

Many people care very little about bats, but nonetheless they play an important role in the ecosystem because of their role as insect-eaters, not to mention that they also pollinate some plants.

How are bats killed by wind turbines? It is not only by collisions with moving turbine blades, but in some cases also by the trauma resulting from sudden changes in air pressure that occur near a fast-moving blade, particularly in large wind turbines.

Mark Hayes of the University of Colorado says that 600,000, although a big number is still a conservative estimate with the possible actual figure 50 percent higher. The data that Hayes analyzed also leads to conclusion that some areas of the United States might experience much higher bat fatality rates at wind energy facilities than others and it has been reported that the Appalachian Mountains have the highest estimated fatality rates in entire United States.

The consequences of deaths at wind farms for bat populations are hard to assess ad give exact numbers primarily because there are no high quality estimates of the population sizes of most North American bat species. Wind farms are just another negative factor in the line for bat populations because these mammals are already under stress because of climate change and disease, in particular white-nose syndrome.


One can not say that using wind energy is perfect from environmental point of view because every source of energy, renewable or not, has some negative environmental effects. In any case, using wind energy is definitely better for environment than staying with fossil fuels. Of course, future technological development must go hand in hand with the protection of species such as whales and bats, and thus we need to make future wind farms, offshore and onshore, as environmentally friendly as possible because this is the only way to ensure sustainable wind energy development.

The overall effect of wind turbines still remains more positive than negative, particularly in comparison to environmental damage done by currently dominant fossil fuels (climate change, different forms of pollution). There is still plenty of room to improvement and wind project developers need to apply different technological innovations in order to minimize the damage done by installation and operation of large wind turbines. Hopefully, future research will provide new environmentally friendly technological solutions for wind turbines. Some positive examples already exist such as for instance equipping turbines with radars to protect birds from colliding with its blades.

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