ENERGY FROM WIND

 Wind energy

Introduction: The hunt for alternative sources of energy is never ending. At present, we use fossil fuels to meet our energy needs, but these are a limited resource. Moreover, when burnt, fossil fuels emit harmful gases such as carbon dioxide (CO₂), which destroys the ozone layer. In recent years, the consumption of fossil fuels has increased dramatically, damaging the environment, our health and our planet. Therefore, it is imperative to find replacements; one such replacement is wind energy. Wind energy is at the forefront of renewable energy resources; it is considered a renewable resource because we are not “using up” wind when we produce energy from it. In addition to this wind power does not cause air pollution.

History of Wind Energy: People have been using wind power for many centuries. As early as 5000 B.C., Egyptians use wind energy to propel boats along the Nile River. By 200 B.C. wind-powered water pumps and windmills with woven reed needles were used to grind grain in Persia. In the 11^th century, people in the Middle East used wind pumps and wind mills for food production. Today, wind tunnels are primarily used to generate electricity.

The process: Most wind turbines consist of three blades that are mounted on a tower. Since the towers are over 100 ft tall, the blades utilise the faster blowing wind prevalent at those heights. Turbines catch the wind’s force with their blades. A pocket of low pressure is created on one side of the blade. The low-pressure pocket pulls the blade towards it, which causes the rotor (the object the blades are attached to) to turn. This action is called lift. The force of the lift is much stronger than the wind’s force against the front side of the blade, which is called drag. The combination of lift and drag causes the rotor to spin like a propeller.

     The rotor than spins a gear attached to it and this gear rotates several smaller motors that connect to a generator. Eventually, the generator turns this energy into electrical energy.

     Interestingly, wind turbines can also be installed on floating structures that can send electricity back to land with the help of undersea cables. These are more efficient as the ocean generates a lot of breeze, which means more energy can be generated. The largest wind turbine in the world is in Hawaii, U.S.A. It stands 20 storeys tall and has blades the length of the football field!

Applications: Wind turbines have no limitation to their use; they can be used for large-scale industrial purposes and even to power a single home. Larger wind turbines are often grouped in wind farms, which have hundreds of windmills. These farms can produce over 100 megawatts of energy.

     Small wind turbines, of up to 100kilowatts, are typically located close to where the generated electricity will be used, for example, near homes or water pumping stations. Small turbines are sometimes connected to diesel generators, batteries and photovoltaic systems. These systems are called hybrid wind systems and are typically used in remote locations, where a connection to the electricity grid is unavailable.

Advantages: Most importantly, wind is a renewable energy source, which means we will never run out of it. In addition to this, it does not cause any harm to the environment. Wind turbines can supply energy in remote places as they do not require a lot of infrastructure. Wind is a domestic energy source, which means it does not need to be transported and the wind can be converted into electricity within the windmill itself. Wind turbines also require periodic maintenance, unlike other power sources.

Disadvantages: Wind fluctuates, which means it is not always reliable. Wind turbines can disturb wildlife such as birds and bats. In some countries, people even cut down forests to set up wind turbines. Wind turbines also generate a lot of noise.

As the world begins to look for more sustainable solutions to the pressing problem of non-renewable energy, wind energy could emerge as an important energy source if more countries start to adopt it.