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.

Conclusion

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.

Wednesday, March 26, 2014

Wind energy development, effects and outlook

Wind energy industry is together with solar energy the fastest developing renewable energy sector with the fairly competitive prices in comparison to currently dominant fossil fuels but this doesn't mean that wind energy can be regarded as the perfect energy source because there are several things wind energy industry will need to improve in years to come in order to become one of the dominant energy source.

To start with, wind energy industry despite being one of the most cost-competitive energy sources is still unable to maintain its current tremendous growth without the adequate incentives and favorable policies, the proof of which is clearly seen from the current situation in United States (wind energy tax credit and the controversies about its prolongation). What this means is that wind turbines will have to significantly drop in prices and will also have to become more effective. Achieving both cost-competitiveness and satisfying efficiency can only be achieved with the help of science. In this sense, the global wind energy industry requires the continuation of technological development as one of the key components that will determine the future of wind power industry.


The benefits of using wind energy

Wind energy is together with solar energy the most popular and most talked about renewable energy source. It is also one of the fastest growing renewable energy industries in the world. There are many benefits of using wind energy and by this I do not mean only environmental benefits.

Using wind energy has many environmental benefits. If world would to make a switch from fossil fuels to wind energy then this would first of all mean fewer greenhouse gas emissions (greenhouse gas emissions contribute to global warming and climate change). Wind energy also doesn't contribute to air and water pollution and has overall very low environmental impact.

Since wind power is a renewable source of energy it cannot be depleted. Wind energy can therefore provide future energy security once fossil fuels become exhausted.

Wind energy has excellent global potential. The global wind energy potential is more than five times more than the world's current energy demand.

More wind energy (instead of sticking with fossil fuels) also means reduced need for foreign fuel import. By developing domestic wind energy sector instead of relying on expensive foreign oil we can give big boost to our economy in form of new jobs, and most of all our money stays inside our borders.

Wind energy can be developed on land as well as offshore, meaning that each country can choose wind energy option that best suits its needs.

Wind power is currently the most cost-competitive renewable energy source. In some areas of the world wind power has already achieved cost-parity with fossil fuels. Wind turbines are also becoming bigger, more efficient and more technologically sophisticated.

The global wind power capacity continues to grow rapidly. There's no doubt whatsoever that wind energy will be a key part of our clean energy future.

Wake turbulence behind individual wind turbines can be seen in the fog in this aerial photo of the Horns Rev wind farm off the Western coast of Denmark.

Environmental effects of wind energy – Not everything is positive

The positive environmental effects of wind energy were already briefly mentioned above, and now we'll say a bit more about this interesting topic.

Using wind energy is lot more environmentally friendly that continuing our dependence on fossil fuels such as coal and oil. This however doesn't mean that using wind turbines is always positive for environment and through this article I will mention certain environmental issues connected with harnessing wind energy and using wind turbines.

Wind energy opponents usually start pouring critics about wind turbines with noise by saying that large wind turbines create excessive noise pollution levels which hurt nearby environment. This is somewhat true because large wind turbines with gigantic blades can produce excessive noise levels and despite the technological advancement over the recent years the noise levels connected with large wind turbines pretty much remained the same. The noise pollution therefore remains the biggest environmental issue connected with wind turbines.

Large wind turbines can also hurt wildlife because birds can be caught by their blades. Birds are not the only animals that can be jeopardized by large wind turbines. The animals that live underground can also be jeopardized because large wind turbines require very deep foundations meaning that their habitats might be destroyed in the process.

Wind energy opponents also complain about the visual look of turbines by claiming that they interfere with the aesthetics of perfect natural landscape as they do not fit in the visual appearance of certain area thus degrading the natural beauty of given environment. This is a highly controversial question because aesthetics is really a matter of personal opinion, so I'll not debate about this issue any longer as this is really more about individual opinion so it is difficult to draw general conclusion about it.

As can be clearly seen from above paragraphs wind energy isn't 100% environmentally friendly source of energy and using wind turbines can also lead to negative environmental impact but this harmful effect is definitely not the reason to move away from wind power and continue our dependence on fossil fuels. The currently dominant fossil fuels such as coal and oil create much bigger environmental damage in form of climate change and air pollution so the environmental damage coming from wind turbines is really negligible compared to environmental damage coming from fossil fuel fired power plants.

This means that replacing fossil fuels with wind energy is much more positive to our environment in comparison to staying with fossil fuels. Of course, the role of the science is vital as it should find new solutions to make wind turbines more environmentally friendly by reducing their noise output as well as equipping them with suitable equipment (such as radars) in order to prevent large bird killings.

Conclusion and future outlook

According to the latest study by Pike Research global wind energy market looks set for the steady growth in the next few years. Pike Research’s report, Global Wind Energy Outlook predicts that by 2017 wind power installations will represent $153 billion global industry.

The numbers in this study predict that in a period 2011-2017 global investment in new wind power capacity will reach $820 billion, and total wind power capacity will grow from current 235.8 GW to 562.9 GW in 2017.

Wind turbines are not only becoming cheaper but are also growing in size which until now weren't considered to be either practical or economical. Wind power is already the low-cost option in many regions, especially in the ones with scarce fossil fuel resources.

Wind power industry will likely continue its growth in years to come, and if everything goes as expected wind power should satisfy more than 20% of world's electricity by the end of this century. There are still some issues like efficiency and intermittency which wind power industry will have to resolve in years to come but nonetheless wind power industry should already look forward to a very bright future.