For centuries, fossil fuels have been the main source of power for the industry and households. Plentiful and comparatively cheap to produce, coal and oil powered the Industrial Revolution and led to the growth of many modern economies. Today, however, we are more and more aware of the harmful effects of these fuel sources. Not only can they be dangerous pollutants, but the supply of fossil fuels is finite. More and more societies and businesses are seeking out sources of energy that won’t run out or cause damage to the environment.
There are many different types of alternative energy sources, ranging from hydroelectric dams to photovoltaic solar panels. Each of them has its own strengths and weaknesses and can work differently in different environments. One of the most common alternative energy sources is wind power.
As a method of producing energy, the wind has a lot going for it. The wind is completely free, produces no pollution and never runs out. The technology of wind power generation is relatively simple, with some similarities to hydroelectric power.
Like water power, wind power relies on turning the energy of a moving substance — kinetic energy — into electrical energy. It does this by means of a rotating turbine; as the turbine spins, it generates electricity. A wind turbine has blades that resemble a propeller, and as the wind spins the blades, a system of gears rotates the turbine.
Like solar power, wind turbines can work either on a large or a local scale. Large areas of wind turbines, called “wind farms,” harness high winds to channel power to a national or regional power grid, while single wind turbines or small groups can provide power to a home or business. In either case, the key to successful wind power generation is location.
In order for a wind turbine to create a reliable power output, it needs to be in a location where it can have regular access to wind. To further complicate matters, not just any wind will do. Most wind turbines have an optimum wind speed. A wind speed between 7 and 25 meters a second is typical for most heavy wind turbines. If the wind speed is too low, it will not be able to turn the blades; if it is too high, the turbine may shut down in order to avoid being damaged.
A wind turbine therefore has to be placed in a location where the prevailing winds will blow at a steady rate. This usually means a high location such as a hill or a wide, flat area such as a shoreline or plain.
Wind turbines come in a variety of sizes and produce a wide range of different power outputs. A large wind turbine such as might be used in a wind farm might put out up to 4.5 megawatts. By contrast, a smaller wind turbine used in the home or at a business might generate around 1 to 6 kW.
The main challenges to wind power as an energy alternative relate to the construction of wind farms. In some regions, the positioning of wind farms in areas of scenic beauty has attracted criticism from conservationists who feel that they spoil the natural balance of the affected areas. Additionally, large wind turbines can be expensive to construct, meaning that they take some years to recoup their costs in energy savings, although smaller domestic-scale turbines can actually be surprisingly affordable as renewable energy sources.