Essay: Advantages and disadvantages of wind power

We use energy to do work. Energy lights our cities. Energy powers our vehicles, trains, planes and rockets. Energy warms our homes, cooks our food, plays our music, and charges our phones. Energy powers machinery in factories and tractors on a farm. Without energy, there would be nothing. There would be no Sun, no wind, no rivers, and no life at all. Energy is everywhere, and energy changing from one form to another is behind everything that happens.
In a world with a constant growing population, and developing technology, the demand for energy is on the rise; however, people are wanting more energy than we can obtain. During the past 100 years, the world demand for energy has gone up drastically. Supplying energy in such huge amounts has caused many problems, such as the limited amount of fossil fuels available today and environmental repercussions. Renewable sources of energy can be used as alternatives to fossil fuels, but much more work needs to be done before they can become the predominant energy source.
Scientists and environmentalists are currently trying to push countries to rely more on renewable sources of energy, rather than non-renewable sources of energy, to not only prevent wastefulness, but to also render the world a greener and more environmental friendly place. There are many different types of renewable energies, however, in this essay I will be talking about one in particular: wind energy.
Wind is a form of solar energy. Wind is caused by huge convection currents in the Earth’s atmosphere, driven by heat energy from the Sun. (Challoner, 1993.) This means as long as the sun shines, there will be wind. This wind flow, or motion energy, can be used to generate electricity when “harvested” by modern wind turbines.
Societies have taken advantage of wind power for thousands of years. Dating back to 5000 BC, when wind was used to power boats to cross the Nile River, it is one of the earliest forms of power that people learned to use. By 900 AD, Persians had already been using windmills for 400 years in order to pump water and grind grain. Windmills may have even been developed in China before 1 AD, but the earliest written documentation comes from 1219 (History of Wind Energy, n.d).
Most wind energy comes from turbines that can be as tall as a 20-story building and have 60 meter-long blades (Wind Power, n.d). These contraptions convert the kinetic energy in the wind, into mechanical and electrical energy. As the wind blows, it spins the blades, which turns a shaft connected to a generator that produces electricity. Finally, fancy power electronic controls convert the electricity into the correct frequency and voltage to feed into the power grid which distributes it to substations, then on to homes, businesses and schools.
The biggest wind turbines are able to generate enough electricity to supply about 600 U.S. homes (Wind Power, n.d). Several wind turbines may be grouped together in windy locations (such as along a ridge) to form wind farms.
Wind is a clean source of renewable energy that produces no air or water pollution. And since the wind is free, operational costs are nearly zero once a turbine is erected. Mass production and technology advances are making turbines cheaper, and many governments offer tax incentives to spur wind-energy development.
However, there are some disadvantages. Some people dislike the look of wind turbines and complain about the noise that the machines make. The slowly rotating blades can also kill birds and bats, but not nearly as many as cars, power lines, and high-rise buildings do. There is also a higher initial cost than fossil-fueled generators. Wind energy is also less efficient than nuclear or fossil fuel energy. It is less efficient because the wind is variable: if it’s not blowing, there’s no electricity generated.
In an ideal situation, 100% of the energy would be converted into electricity. However, converting all of the wind’s kinetic energy into mechanical energy, is just not possible. Some energy must remain in the air leaving the turbine. The “energy in” is the kinetic energy from the wind’s velocity and air density that flows into the area swept by the turbine blades. The “energy out” is the energy converted by the turbine blades into mechanical energy (which is then usually turned into electricity), plus whatever energy is left in the air after it passes through the  turbine rotors. If you are lucky, about 35/40% will be converted into useful energy (Watson, n.d.).
Overall, the advantages of wind power heavily outweigh the disadvantages. Although it can only supplement other sources of energy for now, it provides skilled jobs for people in rural communities, replaces environmentally harmful energy sources, and is inexhaustible. It will never be affected by ‘price shocks’ caused by international conflicts, and unlike oil fields, wind energy will never not be renewable.
In conclusion, the wind energy industry is booming. Germany has the most installed wind energy capacity, followed by Spain, the United States, India, and Denmark. Development is also growing in France and China. With today’s technology, wind energy could provide 20% of the United States’ electricity (around the amount nuclear power provides) with turbines installed on less than 1% of its land area. And within that area, less than 5% of the land would be occupied by wind equipment. By the year 2020, 10 million average American homes could be supplied by wind power, preventing 100 million metric tons of CO2 emissions every year (Wind Power, n.d.) Lessening our dependence on fossil fuels is critical to the health of all living things, and wind energy can do just that.