generated as well. About 70-85 percent of the electricity that is used for pumping water can be recaptured once the water is released.
Similar to power stations using hydro-electricity, pumped storage stations can also supply electricity when demanded. It is literally controlled with just a turn, on or off the tap, at the pumped storage system.
Wind Turbines
Wind power has been popularly used for thousands of years to operate the machinery that grinds wheat, pumps water or powers farming equipment. The first test in using wind to generate electricity was conducted in 1887 in Scotland. The production of wind turbine in the U.S. followed the next year. In 1908, 72 wind turbine electricity generators came on the scene in the U.S.; by the 1930s it was common to see these wind turbines at many of the nation’s country farms.
Wind turbines work by rotating on a horizontal axis with three to five blades, an electrical generator and a gearbox. The turbine is positioned to face the wind in order to generate the desired or required electricity. Pointed small generators make use of a wind vane, while electric motors power the bigger generators to direct the turbine head to capture the wind.
Wind turbines work best at high altitude, where a good airflow can be experienced with minimal turbulence. Bigger turbines are able to produce 2- 6 MW (megawatts) of electrical power, an amount sufficient to power up 2,000-6,000 homes.
For small homes and businesses, small wind turbines have been found to be suitable for the task, with a production of 0.5-6 kW electricity.
The main contention with wind turbines is that they are capable of generating electricity only when the wind blows and energy is not always available when it is needed (i.e., on demand). Hence, it is a challenge to integrate them into a power grid. The best way to use them still – at least until the storage snag has been resolved - is for supplementing more dependable electricity sources. Wind turbines cannot yet be used to replace other sources entirely, but they are an excellent resource, nonetheless, for reducing our dependence upon oil, coal and nuclear generated energy.