Wind energy is derived from solar resources. When sunrays cause heat to be spread in the earth’s atmosphere, a motion starts in air. This motion in air is called wind. However, the propensity to absorb heat amounts at the various layers of the earth’s atmosphere is not the same. The surface of the planet, with its sea bodies, oceans, hilly areas and plain lands, is not uniform either. The amount of currents of air that a particular region receives is different from that in another area. During the time of day, the sun beats down, and air, getting heated up, becomes less dense, and moves in the upward direction. The blank space thus created is soon taken over by the heavy, denser air that moves in quickly from the areas that lie near.
Wind has been historically used by mankind to ensure the smooth sail of their ships. Between the 40 degrees South and 50 degrees South latitudes of the Earth, the well-known Roaring Forties created, using its winds, the Clipper Route. The last-named route provided an easy, and quicker than average sea path between the countries of England and Australia. This route was created across the Indian Ocean. Moving into several areas that had never been explored before also became easier for the sailors, with the various forms of available sea trade winds.
The current world is witnessing a lot of supply hassles of the fossil fuels. The conflicts among the middle-eastern countries that produce oil have further pulled down the available amounts of petroleum and related products. The level of accumulation of the harmful greenhouse gases is on the rise too. However, no such potential risk of supply crisis is faced by wind energy systems for the simple reason that, as long as the sun exists, wind will remain blowing. Hence, wind is gradually gaining in importance as the chief resource for the generation of electricity. The importance of the wind resource is further highlighted by the fact that it can be easily renewed.
Grinding of corn, pumping of water as well as cutting of wood at a sawmill were done by the primitive inhabitants of America, by making use of windmills. The present day engineers derive their inspiration from those techniques. Although the sophisticated windmills do not look like those of earlier days at all, the former has been proven to be highly efficient for the purpose of electric power production. In the first half of the decade of the eighties, California utilized more than twice the amount of wind energy, compared to any other sates of the US, and was easily the leading electricity producing state in America. All the electrical power in this case refers to that produced by equipments driven by wind energy. Cape Cod, Massachusetts is chosen as the venue (at a local coastal area) for the very first Wind Park of the world. Various forms of wind-driven machines (including windmills) would be analyzed there.
In the United States of America, the principal types of wind turbines or windmills are two in number. These are the units with a vertical axis and those that have a horizontal axis. Over time, the latter machines have become much more popular than the former. The breadth of these horizontal axis machines is 200′ (across), they are as high as a building with 20 floors, and have blades that look like the propellers of an airplane. The hugeness of the blades of the biggest ever wind-drive machine can be imagined by the fact that the latter are even larger than a football field. This wind machine can tap in the largest amounts of wind energy.
When electric power is produced on a mass scale, by keeping a large number of wind driven equipments together, the place is called a Wind Farm (or, a Wind power plant). The largest wind power plant of the world has the capacity to serve the electrical requirements of more than 220,000 households annually. This wind farm is located at Texas, and is named the Horse Hollow Wind Energy Center, with 421 wind turbines. Independent power producers mostly own these power plants, and ownership by companies of public utility is rather uncommon. The production and sale of electricity is carried out by the individual owners themselves.
The United States, in most of its areas, has the good fortune of having favorably high wind speed levels. These speeds of wind determine how efficient a wind turbine would be, and can indeed vary across regions, apart from having seasonal variations. For example, in the summer months, many households can use air conditioning units. This is because of the adequate amounts of electricity generated from the strong winds that blow here from April to October. As a result, the Mojave Desert experiences a strong rise in temperature, and the hot air above it rises up. Heavier, cooler, denser air quickly moves in from the Pacific Ocean to fill the vacuum thus created. Availability of electricity in Montana is more in the months of winter, due to the winds being more strong here during this period. Hence, central heating systems are used by many inhabitants of this area.
Apart from electricity generated from solar energy, wind energy represents the most eco-friendly method to produce electrical power. Apart from being eco-friendly, wind energy does not contaminate the atmosphere. Its fuel (wind) is free and is in abundant supply at all times. In solar power systems, no maintenance services are required either, since the former do not have mobile components. However, in wind energy systems, maintaining the original structure and shape of the shafts that would rotate is required.
For cutting down on the high levels of electricity bills, installation of a wind energy system is an ideal option. Environmental cleanness would be obtained as an added advantage. However, the following factors need to be looked into, before a wind energy unit can be set up:
i) Where to set up the system in the home,
ii) How to install the system correctly,
iii) The techniques of completion of the wire networks,
iv) The places from where free batteries and other system parts can be acquired, and
v) The required measures for precaution.