Wind energy is converted into useful energy by means of wind turbines that produce electrical power, wind pumps and windmills that produce mechanical power. Wind energy is renewable, clean, widely distributed and does not emit greenhouse gases during operation. Higher altitude winds are stronger and consistent. Unlike other energy forms, wind power is less affected by the environment.
In 2010, it was reported that the need for wind energy is growing at a rate of over 25% per annum. According to 2011 reports, nearly 83 countries across the world make use of wind power for commercial purposes. It was estimated that Denmark uses wide energy for generating wind power to meet more than a quarter of its electricity needs as of 2011. The Small Wind World Report submitted by the World Wind Energy Association (WWEA) in March 2012 reported that around 656000 small wind turbine units with the total capacity of 440 MW have been installed at the end of 2010 following 521000 units in 2009 and 460000 units in 2008. China and the USA have the largest number of small turbine units globally with 450000 and 144000 units, respectively.
Types of Wind Energy
The following are the types of wind energy generated using wind turbines:
Onshore Wind Energy
Onshore wind facilities are capable of providing energy security, reducing CO2 emissions and supplying electricity to remote locations. Onshore wind power has become one of the most inexpensive energy forms. More than 343 onshore projects are available in the UK alone. Moreover, it was estimated that a single modern turbine with a capacity of 2.5MW is capable of generating 6.5 million units of electricity annually.
Offshore Wind Energy
Although offshore wind farms are expensive to construct, they are capable of generating 8 TWh of electricity yearly, which is equivalent to the electricity consumption of nearly 2 million homes.
Small and Medium Scale Wind Energy
Small and medium scale turbines are nearly 55 m tall and are capable of producing sufficient amount of energy to meet the country’s energy demand. The energy produced can be fed to the electric grids or stored in batteries for future use.
Wave and Tidal Power
Energy carried by ocean surface waves is converted to an useful energy form known as wave power. Globally, the estimated energy produced from wave power is 2 TW. Tidal power, on the other hand, is produced by the conversion of the energy of tides.
The Pros of Wind Energy
The advantages of wind energy are listed below:
- Wind can be captured efficiently using modern technology.
- Energy produced from a wind turbine is free of pollutants and green house gases.
- Construction of wind turbines requires only a small part of land. This is beneficial, in particular, for agricultural areas as the land below turbine can still be utilized.
- Wind turbines are available in various sizes to benefit small town and cities.
- Wind turbines are useful for remote areas without electricity.
The Cons of Wind Energy
The disadvantages of wind energy include the following:
- Wind strength does not remain constant always. Hence the energy produced by the wind turbines is not the same all the time.
- Manufacturing and installation of the wind turbines may cause pollution.
- Wind turbines generate noise during operation. Hence these turbines are not built in the countryside.
- Large number of wind turbines is required to produce energy sufficient for the whole community. For instance, the largest turbine currently available can produce energy to power only around 475 homes even when operated at full speed.
For centuries, people have been harnessing wind energy to sail ships or to power windmills and this forms as a basis for today’s modern wind turbines. These turbines can be either used as stand-alone applications or combined with a power grid. The UK generates more wind power than any other countries in Europe with the help of large-scale wind turbines in both offshore and onshore locations.
The number of wind turbines installed globally is increasing rapidly in spite of the fact that they are expensive to construct and maintain. However, with the growth of the industry and increasing electricity demands, the cost of generating electricity by means of turbines would fall gradually over the years. The WWEA predicts a total global small wind capacity of 3800 MW by 2020, which is almost ten times greater than that achieved in 2010. In addition, the capacity of the new small turbines is also forecasted to increase to 750MW by 2020. With the increasing growth rates, the wind sector will likely develop in near future to facilitate energy security and provide a sustainable environment.
Sources and Further Reading