The greatest challenge of the 21st century is filling the gap between energy demand and supply with clean, reliable and green source of energy. Energy is very essential and it is in material form in everything that is around us. The opportunity cost of obtaining the energy that we require is the impact that is made on our environment. Some energy sources have greater impacts while others have relatively lesser ones. All sources of energy affect the environment in one way or the other. There is absolutely no such thing as an entirely clean source of energy. (Boyle & University, 2004)
There are primarily two sources of energy:
Non- Renewable Energy Sources- These sources of energy cannot be replenished. They have been used as a source of energy for thousands of years. Oil, natural gas, coal, uranium (all commonly known as fossil fuels) are examples of non-renewable sources of energy. They are formed from organic remains of prehistoric animals and plants.
Renewable Energy Sources- These sources of energy can be renewed and can be replenished in a short span of time. Sources include wind, solar, biomass and hydropower.
A non-renewable source of energy is defined as a good which if used in a greater quantity today will be available in much less quantity tomorrow. Fossil fuels have been used as a source of energy since time immemorial and till today almost 93% of all power generation is done through this source. This source provides us with efficient and good quality energy however, it has several problems associated with it as well. Fossil fuels cause severe damage to the environment. When fossil fuels are burnt several gases are emitted and one of the most significant amongst them is carbon dioxide. This gas traps heat in the earth's environment and causes global warming. Over the past 150 years, a 25% increase in the levels of this gas has been recorded. If conditions like this persist the next century will be warmer and glaciers will continue to melt and extreme weather conditions will be faced. Apart from this, gases like carbon monoxide, sulphur oxides and hydrocarbons are released into the atmosphere which contaminate clean air and make it a serious health hazard. Land and water pollution cause issues to wild life and disturb the natural ecosystem.
In order to combat these problems it is important that alternatives to this source of energy be found. Non- renewable sources are already limited in supply and it is not known to us when the last drop of oil will flow or when we will extract the last bit of coal and thus we must properly manage our resources. (Boyle, 1996)
Global climate change is one of the greatest threats to the future of mankind. This change is due in large part to emissions of "greenhouse gases" which inevitably result from the production of energy using conventional fuels. It is considered to be a fact that the development of renewable energy sources and especially wind energy is the only -- medium term solution to the problem of climate change. (Kruger, 2006) (Boyle, 1996)
It is because of this that many countries have moved towards generating power by using this source. Just in the first half of 2011 the numbers of countries using wind to generate electricity increased to 86 and almost all wind turbines which have been installed worldwide have the ability to generate 430 TW per year which equals almost 2.5% of the global electricity consumption. Wind energy is the second largest renewable resource which is available to us after solar power and it has the potential to produce a total of almost 3600 TW of energy which is more than enough to supply human energy needs by 200 times. Just recently wind became Spain's biggest source of energy. (Boyle, 1996)
Generation of electricity by wind energy has the potential to reduce impacts on the environment which are caused by fossil fuels which generate atmospheric contaminants and thermal pollution. Wind is considered by many to be the greenest source of energy and has attracted governments, organizations and individuals alike in order to change the dynamics of the traditional ways of generating electricity and adopting this method as a way to make power.
Wind energy does not burden the local environment with dangerous gas emissions. Using wind energy to generate power reduces the discharge of carbon dioxide gas which traps heat in our environment. Wind farms are able to reduce the emission of this greenhouse gas by almost 20000 tonnes. Naturally it would take a 4000 acre forest to remove as much carbon dioxide from the atmosphere. Apart from carbon dioxide emission sulphur dioxide emission is also reduced. This gas is a by product of burnt fossil fuels and reacts with others chemicals to form acidic compounds that lead to acid rain. Acid rain is a great threat to lakes and forests as it raises the levels of acidity and damages the natural habitat. Wind farms cut sulphur dioxide emissions by almost 120 tonnes every year. There is no threat of nuclear breakdowns and leakages which can affect generations adversely. (Boyle & University, 2004)
Using wind to generate electricity helps sustain and store non-renewable sources of energy. Wind is renewed every day. For almost every KWh energy that is generated by wind we save one pound of coal which means we save almost 13000 tonnes of coal every year. Generation of wind power uses comparatively less land. Only about 5% of the wind farm site contains all the equipment, turbines and access roads while the remained 95% of the land. Wind power contributes to the decentralization of the energy system and it reduces the loss of energy during transmission processes. It also provides energy security and we are not under the constant threat that we will run out of sources to produce energy in the future. Wind is free and is provided to us by nature in abundance. An average turbine, over its 20-year life time will provide almost 80 times more energy than used at the time of its construction.
Another major environmental benefit of using wind to generate electricity is that it reduces the impact on water. Water is another precious natural resource and is a home to millions of aquatic wildlife. These aquatic animals live, feed and breed in the same water and when it is used as a source of generating electricity these animals are affected. Large dams and reservoirs have to be built and power stations have to be installed. Existing water flows become disrupted and floods occur in nearby areas. The entire water system because of this gets out of place. Also, nuclear and coal powered plants used 500 times more water than a wind turbine does. Thermal power productions withdraws more water than does the agricultural sector of a country and thus by using wind to generate power the pressure which is placed of the water resources is greatly reduced and is beneficial for our environment. (Kruger, 2006)
However, just as there are so many potential environmental benefits of power generation by wind there are many arguments which do not support the statement that wind energy is green. Several researches have been conducted over the past several decades to study whether or not renewable sources of energy are in fact as green as they are claimed to be. Although wind power plants have a relatively lesser environmental impact than fossil fuels power plants, concerns have been raised over the noise that is produced by the rotor blades, the deaths of birds and bats that fly into these blades and the visual impacts. (Kruger, 2006)
Environmental assessments are carried out and potential impacts of wind plants on the natural habitat of animals are evaluated before they are set up. There are a few ways in which wind turbines interfere with birds and bats and one is the potential impact on their natural habitat. Collisions with wind turbines have been an issue for quite a while. Poor sitting and out dated turbines greatly affect the lives of these animals. In the United States, in 2001 an estimated 2.2 birds were killed by each turbine and every year almost 100 million birds are killed. 12% of the worlds almost 10000 bird species face extinction because of wind turbines.
Wind turbines cause a great deal of noise pollution as well. In wind turbines noise can be emitted from two sources. The first source of noise is from the movement of mechanical parts like the gear box, bearings and electrical generators while the second source is caused by the movement and constant revolution of the wind blades. Even though modern wind turbines are relatively quite in relation to the older machines, noise pollution is still a problem and can cause nuisance especially if the wind power station is located near a residential area. Noise pollution can have adverse affects on the lives of people who live nearby. It can cause stress…