What is wind energy? Wind is the movement of air from an area of high pressure to an area of low pressure. This occurs because the sun heats the surface of the earth unevenly. As some particles of the air get heated, they move higher in the atmosphere and their place is taken by cooler particles. Wind energy is the energy that comes from this movement. It can be used to produce electricity with the use of wind turbines.
Facts: In 2010 wind energy consisted of 2.5% of total electricity production. In 2011 83 countries around the world used wind energy. Since 2006 global capacity of wind energy has risen to 70.000 megawatts. Germany has the most wind energy plants followed by Spain, United States, India, and Denmark. Experts claim that if this trend continues, by 2050 one third of the world’s electricity will be produced by wind.
How wind turbines work? Most wind energy comes from wind turbines. Turbines catch the wind’s energy with propel – shaped blades. Usually two or three blades are mounted on a shaft to build a rotor. As the wind moves the blades, it produces electricity through a generator. This electrical current is passed to storage facilities and later connected to the electricity grid.
A wind blade acts more or less like an airplane wing. When the wind blows, a pocket of low pressure air is gathered at the down part of the blade. This portion of air pulls the blade toward it and causes the turbine to move. This is called a lift. The force of the lift is much stronger than the force that the air applies on the upper part of the blade, which is called a drag. The combination of lift and drag causes the turbine to move like a propeller. The turning propeller spins a generator to produce electricity.
Wind farms: Wind farms consist of hundreds of wind turbines built at a particularly windy spot and connected with each other through a network. The electricity produced is transferred to the main electrical supply system. Wind farms can be located onshore or offshore. Onshore wind farms can produce electricity at a relatively low cost. The land between the turbines can be used for agricultural purposes. Turbines are interconnected with a medium voltage network. At a substation the medium voltage is transformed to high voltage and then passed on to the main grid. Offshore wind farms are the farms built at sea. They provide electricity in a more stable way because they are powered by the frequent and strong wind currents that exist ashore. Their construction cost is much higher.
Advantages: Wind energy is plentiful, renewable, and inexhaustible. It can be a sustainable solution to reduce green-house emissions, prevent environmental pollution and mitigate the effects of global warming while at the same time covers our needs for electricity. The operational costs of wind farms are low because once they are set up no additional fuel is needed. Mass production and advances in technology make the cost of producing wind energy lower. Furthermore, many governments establish tax incentives in order to help the field boom.
Disadvantages: One of the main disadvantages of wind energy is that wind power varies from one day to another. This can cause fluctuations of the electricity. Rotating blades can kill birds and other animals. As the voltage produced by a wind farm increases the electricity grid has to be updated. This can be quite expensive.Possible solutions to these problems can be storing electricity for later use, installing geographically distributed turbines, transferring power from one area to another and reducing electricity production when the demand is low. What is more, wind farms can be built in adequate locations where they will not put wildlife in danger. The weather forecast can give information about the changing weather conditions and how these can affect the electricity production.
Conclusion: In an era when the protection of the environment becomes so important, it is imperative to further invest in wind power technologies. This can lead to a sustainable future where economic development can be combined with environmental protection and sustainability.