Wind turbines a boon to the environment or a landscape scar

Wind turbines, a boon to the environment or a landscape scar?

Wind power accounts for 4.58% of the worlds renewable energy sources (Global Status Report 2006) A turbine itself is defined by the American Heritage Dictionary as a “rotary engine in which the kinetic energy of a moving fluid is converted into mechanical energy by causing a bladed rotor to rotate” (2003). In the case of wind turbines, it is the kinetic energy of air particles that is used as a source. It is generally accepted that the history of using wind power as a method of generating electricity commenced with the success of Charles Brush, from Cleveland, Ohio, in 1888 (Danish Wind Industry Association, 2003). However, wind turbines are not universally popular. On one hand, they are seen as being an inefficient ‘eyesore’, whereas others contend that they are the answer to the world’s growing environmental problems and energy shortages. This essay will attempt to provide a balanced view of both arguments. The environmental impact of wind turbines will be analysed with regards to disruption to wildlife, the physical visual and aural impact of wind turbines, and finally global warming and pollution.

The first area under consideration when analysing the environmental footprint of wind turbines is the impact on wildlife. Existing ecosystems are an important part of a healthy environment, and any attempt to install wind turbines must take these into account. The first aspect here is the potential for increased mortality of any birds in the area. The wind turbines could potentially kill birds in two ways: if they are turned off for long periods and birds approach or sit on the rotor blades; and also through collisions in periods of poor visibility (including darkness). For example, in a study conducted on wind farms on the Straits of Gibraltar, Griffon vultures were killed at a rate of 0.15 birds per turbine per year, and common kestrels at a rate of 0.19 birds per turbine per year (Barrios and Rodriguez, 2004). This could be significant for rare birds or those with low reproductive rates and long life-spans. However, no significant impacts have been recorded in the United Kingdom to date (Drewitt and Langston, 2006). The other significant aspect here is interference with migratory paths or habitat, as birds avoid areas with wind turbines. Drewitt and Langston (2006) have completed a summary of current research and have concluded that there are some links between wind turbines and birds being negatively affected in this way, but that there is also a possible benefit in that offshore wind turbine foundations can act as an artificial reef, increasing the number of fish species in the general area. However, for the most part any problems can be managed by careful planning of the location of potential wind farm sites.

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Another aspect to examine is how the visual presence and noise of wind turbines can spoil the beauty of nature. Wind turbines are not generally small structures so are usually visible for several kilometres. The average size of a commercial land based wind turbine from base to the tip of the rotor is approximately 135 metres (American Wind Energy Association, 2007). Furthermore, the best locations tend to be in exposed areas, especially coastlines, where there is more consistent wind flow. Another factor restricting location is that the wind generation cannot be too far away from where it is consumed as so much energy is lost in transferring the power here, meaning that wind farms currently usually need to be near human developments. One 1.8 MW wind turbine at a reasonable site is capable of producing over 4.7 million units of electricity each year, this is enough to power over 1000 households or power a computer continuously for over 1,620 years. Unfortunately, although a lot of people support renewable energy in theory, many seem to have adopted the philosophy of “not in my backyard”. In other words, they realise the need for renewable energy but they do not want to have to see wind turbines when they look out of their windows. When the Awel Aman Tawe wind farm project in Wales was assessed in terms of community concerns and support, research shows that the biggest areas of concern included the visual aspect, as well as the noise that wind turbines could cause (Hinshelwood & McCallum, 2001). However, the visual presence could be mitigated in several ways. Firstly, there is the option of many small wind turbines, such as a wind turbine on the roof of everyone’s houses. People would soon become accustomed to seeing them and they would blend in with surroundings, as is the case with TV satellite antennas today. Also, architects today are making the wind turbines more aesthetically pleasing and much quieter (Twidell and Weir, 2006). Another potential solution is placing them in areas of existing human development so as to avoid disturbing untouched countryside, such as alongside motorways

Table 1

The above table is showing the current wind farm projects in the UK, the number of turbines that would be required for those sites, the total amount of power that could be produced, how many homes would be power by the electricity generated and lastly the reduction of harmful by-products if wind energy was to be used as the power source (BWEA 2007)

The last point to consider is the impact of wind turbines on pollution levels. Pollution is a negative impact, usually chemical emissions, which do not naturally occur in the environment. One of the primary concerns for the world at the moment is global warming. Power generation has a major role to play in the production of greenhouse gasses as burning fossil fuels releases carbon dioxide into the atmosphere. For example, typical coal plants emit more than 1.0kg of CO2 per kWh produced, and geothermal plants 0.1kg (Twidell and Weir, 2006). Even hydroelectric plants may cause significant amounts of methane to be released into the atmosphere, if rotting vegetation is allowed to lie in the dam as it fills. Other pollutants often released in power generation include sulphur dioxide, which causes acid rain, and nitrogen oxides, which lead to smog (National Academy of Sciences, 2007). Wind turbines avoid this problem, because they do not produce any form of waste while running. The latest wind turbine design from the German manufacturer Enercon, one of the largest manufacturers in the world, even avoids the use of oil to maintain the wind turbine, by an innovative gearless drive system (Enercon, 2007). The manufacturing process of wind turbines should also be considered, in terms of any waste products created. Although there has been some criticism here, several projects have been initiated to create the world’s first recyclable rotor blades (NetComposites, 2004, InderScience Publishers, 2007). Other developments have increased the lifetime of rotor blades, hence reducing the cost of energy (Sandia National Laboratories). Furthermore, the manufacturing process of many other power supplies can also have detrimental environmental effects, such as the noxious chemicals produced when making photovoltaic panels for solar energy collection (Twidell and Weir, 2006). On balance, wind energy seems like a positive step forward in terms of reducing carbon emissions and other negative waste products.

Wind turbines are an important part of electricity generation, because they are a renewable energy source. As long as the wind is blowing, we will always be able to generate power. In today’s world of climate change and limited fossil fuels and increasing energy demands it is important to find an environmentally friendly solution to power needs. In this essay we looked at the environmental effects of wind turbines, considering local bird life, the physical impact of turbines, as well as their impact on reducing greenhouse gasses that contribute towards global warming and other pollutants. Although there are important environmental issues to consider, with careful planning any adverse effects can be mitigated using the solutions outlined in this essay. When one considers the lack of pollutants caused by wind turbines as opposed to traditional methods, one can see real environmental benefits to be gained if wind turbines become a bigger part of power production.

References

American Heritage Dictionary of the English Language (2003) 4th edition. (accessed 2 November 2007)

American Wind Energy Association (2007) Wind Energy Basics (accessed 2 November 2007)

Barrios, L and Rodriguez, A (2004) ‘Behavioural and environmental correlates of soaring-bird mortality at on-shore wind turbines’, Journal of Applied Ecology, 41, (1), 72-81.

Danish Wind Industry Association (2003) A Wind Energy Pioneer: Charles F. Brush (accessed 1 November 2007)

Drewitt, A and Langston R (2006) ‘Assessing the impacts of Wind Farms on birds’, Wind, Fire and Water: birds and renewable energy, 148, (s1), 29-42

Enercon (2007) Technology – Drive System – Direct Drive (accessed 2 November 2007)

Energy Information Administration (2006), World Consumption of Primary Energy by Energy Type and Selected Country Groups, 1980-2004. (Accessed 1 November 2007).

Global Status Report (2006), Renewable Energy Policy Network Policy for the 21st Century,(accessed 3 November 200)

Hinshelwood, E and McCallum, D (2001) Examining Approaches to Renewables Consultation – Lessons from the Awel Aman Tawe Community Windfarm Project ETSU K/BD/00236/REP

Inderscience Publishers (2007), Recycling Wind Turbines (Accessed 2 November 2007)

National Academy of Sciences (2007) NAS Briefing Environmental Impacts of Wind Energy Projects Summary (Accessed 2 November 2007).

NetComposites (2004) Irish Company Signs Agreement with Mitsubishi Heavy Industries and Cyclics to Cooperate in Development of Thermoplastic Composite Wind Turbine Blades www.netcomposites.com/news.asp?2502 (Accessed 2 November 2007)

Sandia National Laboratories (2007). More Efficient Wind Turbine Blade Designed www.sciencedaily.com /releases/2007/03/070319180042.htm (Accessed 2 November 2007)

Twidell, J and Weir, T (2006) Renewable Energy Resources (2nd edition). Oxon: Taylor & Francis

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