Wind Power Basics
Wind is moving air. The engine that drives this movement is the sun. A good illustration is the sea breeze that blows along the Texas Gulf coast. As the coastal land soaks up sunshine, the air above it heats up and rises. Air over the cooler ocean water then rushes inland. The result is a very dependable wind source suitable for making anything from electricity to windsurfing.
Although modern wind turbines can produce some electricity in light winds, the stronger the breeze the better. The power available in the wind is proportional to the cube of its speed. That means that if the wind speed doubles, say from 10 to 20 miles per hour, the power available to a wind generator increases by a factor of eight, for instance from 1,000 Watts to 8,000 Watts.
One easy way to access higher wind speeds is simply to go higher above ground level. Winds high above the ground are stronger than winds near the ground. On average a five-fold increase in elevation, say raising the height of the wind machine from 10 feet to 50 feet, will result in twice as much available wind power. That’s why wind turbines are perched on tall towers and are often located on mountains or hilltops.
Given the need for strong winds, finding the best sites for commercial wind farms is critical. The location of power plants fueled by wind should be near existing power lines and in the windiest sites available. To compete head-to-head with fossil fuel generating technologies, wind turbines are best located in areas where wind speeds are 16-20 mph at 50 m height.
Air temperature is also an important factor in wind power generation. Cold air is denser than hot air. Thus, wind turbines are able to generate about 5% more power at any given wind speed in the winter than they are during the hot days of summer.
Making Watts from Wind
The blades on a wind turbine are similar to the propeller blades on an airplane. The rotor blades generate lift from the passing wind, causing them to rotate the hub of the turbine. The rotating action of the hub then turns a generator, which creates electricity. A gearbox is generally necessary to optimize the power output from the machine. That power is then either fed into the electric grid or stored in batteries for use on-site.
While wind speed is important, so is the size of the rotor. On a turbine, the power available to the blades is proportional to the square of the diameter of the rotor. In other words, simply by making the turbine blades twice as long and beefing up the generator, you increase the power producing capability of the turbine by a factor of four. Modern wind turbines come in two varieties: horizontal axis and vertical axis. Horizontal axis turbines have blades that spin on an axis that is parallel to the ground. These systems often look like the propeller on an airplane. Vertical axis systems have blades that spin on a vertical axis giving them an appearance somewhat like giant eggbeaters.
Although large utilities are getting the most attention for their move into wind power, rural residents in all 50 states and dozens of foreign countries have quietly been installing small-scale wind generation systems. These systems can be obtained for as little as $1,000 and are perfect compliments to solar photovoltaic systems. Several vendors sell ready-made towers and turbines that are easily installed.
Wind Power in Practical Applications
Wind energy uses the energy in the wind for practical purposes like generating electricity, charging batteries and pumping water. Large, modern wind turbines operate together in wind farms to produce electricity for utilities. Small turbines are used by homeowners and remote villages to help meet energy needs for a vast array of applications. GenPro Energy focuses on small wind energy systems from 0.4kW to 100kW.
Bergey Windpower is one of the world’s leading suppliers of small wind turbines. With installations in all 50 U.S. States and more than 90 countries. Bergey's turbines are also used for off-grid homes, for rural electrification, and to boost the performance of solar electric systems.
Southwest Windpower is the world’s largest producer of small wind turbines. You can find them used on everything from remote cabins to sailboats and other applications including utility connected homes. The Skystream 3.7 - Southwest Windpower's revolutionary small wind turbine - is now available.
According to the U.S. Census, more than 17 million homes in America are located on land that is appropriate for a small wind system. Could your home be one? GenPro Energy Solutions has certified installers for the SKYSTREAM 3.7 Wind Turbine. If you would like to see a working SKYSTREAM 3.7 please contact us for a demonstration.View our selection of Wind Turbines.
