About Wind Energy
What is wind-energy?
In reality, wind energy is a converted form of solar energy. The sun's radiation heats different parts of the earth at different rates - most notably during the day and night, but also when different surfaces (for example, water and land) absorb or reflect at different rates. This in turn causes portions of the atmosphere to warm differently. Hot air rises, reducing the atmospheric pressure at the earth's surface, and cooler air is drawn in to replace it. The result is wind.
How is wind-energy captured?
A wind energy system transforms the kinetic energy of the wind into mechanical or electrical energy that can be harnessed for practical use. Mechanical energy is most commonly used for pumping water in rural or remote locations - the "farm windmill" still seen in many rural areas of the U.S. is a mechanical wind pump - but it can also be used for many other purposes (grinding grain, sawing, pushing a sailboat, etc.). Wind electric turbines generate electricity for homes and businesses and for sale to utilities.
How do wind turbines work?
There are two basic designs of wind electric turbines: vertical-axis, or "egg-beater" style, and horizontal-axis (propeller-style) machines. Horizontal-axis wind turbines are most common today, constituting nearly all of the "utility-scale" (100 kilowatts, kW, capacity and larger) turbines in the global market. Wind turbines use wind to make electricity. The wind blows on the blades, which causes the blades to turn. At the top of the turbine is a box called the nacelle, which houses all the internal mechanisms of the turbine, including the generator. The blades turn a shaft within the nacelle. The shaft is connected to a gearbox which multiplies the rotation speed. There is a shaft, connected from the gearbox to the generator which causes the generator to spin and thus create electricity. The electrical output is then fed into a transformer, which converts the electricity from the generator (usually 750 volts) to a range of different voltages (normally about 34,000 volts). The grid supplies high voltage in order to transmit power across distant areas.
Wind Energy: then and now
Wind power is both old and new. Since the beginning of early recorded history, people from all cultures have been using the wind as a natural resource to propel ships, pump water and to grind grain. Over time, however, the early windmill has evolved from basic paddles on a wheel to three-bladed, freestanding power-generating machines that can stand as tall as a 20-story building!
In the United States, the original "glory days" of wind was between the years of 1870 - 1930, and was used primarily to pump water to irrigate the farming communities. When grid-connected electricity was finally introduced, windmill usage tapered down. However, the interest in wind power was reborn during the energy crisis of the 1970's. Although windmills were reintroduced, it wasn't until the 1980's that the state provided tax incentives to promote wind power when pushed by a myriad of energy problems: the high cost of fossil fuels, a moratorium on nuclear power, and concern about environmental degradation.
In the early 1990's, improvements in technology coupled with lower costs of production resulted in increased wind turbine reliability and provided another boost for wind-power development in the country. Concern about global warming and the first Gulf War led Congress to pass the Energy Policy Act of 1992. The Energy Policy Act of 1992 was a comprehensive energy legislation that included a new production tax credit for wind and bio-mass produced electricity. Shortly thereafter, the entire electricity sector began to anticipate a massive restructuring. It wasn't until 1998 that the wind-energy sector began to experience continuing growth in the United States, thanks in large part to federal tax incentives, state-level renewable energy requirements and like incentives.
Europe and Asia, are capable of meeting a lot of their electricity demands through wind power with a lot less land and resources compared with the United States.
Environmental protection and clean-energy development are now top priorities worldwide, and we all must carefully consider how we can produce the energy that we consume.
Increased usage of efficient energy-generating systems that do not negatively impact the environment must take effect. The popularity of using wind as an electricity generating resource stems from the fact that it is extremely clean, renewable and highly efficient. Today, wind energy is one of the lowest-priced renewable energy resource available today, costing between 4 - 6 cents per kilowatt hour.
