A wind power generator is any device that converts wind energy into a usable form of energy. The most common type of wind power generator is a three-bladed wind turbine, which transforms wind energy into electricity. The wind power generator is becoming an increasingly popular form of power generation, as many nations turn away from traditional petroleum energy sources and towards renewable sources.
In some ways, anything used to convert wind energy from one form to another can be looked at as a wind power generator. From this perspective, even something as simple as a sail on a sailing ship could be viewed as a wind power generator, transforming the wind into momentum for the ship. A windmill directly attached to a water pump or a grain processor could also be looked at as a wind power generator. This early sort of wind power generator was in use as far back as the 2nd century BCE in Persia, and the technology spread throughout the world over the next few millennia.
More commonly, however, a wind power generator would be looked at only as a device that transforms wind energy into electricity. In this sense, the earliest devices appeared in the late 19th century. By the end of the first decade of the 20th century, there were nearly 100 electric generators attached to windmills in the United States, with some producing as much as 25 kW. Throughout the 1920s and 1930s the wind power generator continued to rise in popularity in the United States, acting as a source of small amounts of electrical power in rural areas which were not attached to any sort of centralized grid.
With the advent of a more robust national electrical grid, powered by coal and nuclear plants, the use of the wind power generator decreased in the United States. Although still used in the 1960s and 1970s on farms for things such as pumping water, few generators were used to actually produce electricity. Beginning in the 1980s this started to change, with the modern wind power generator making an appearance, and a growing interest in alternative energy sources to oil.
The modern wind power generator is usually on a horizontal axis, with three blades to it. The generator changes direction to face the wind, as determined by a simple computer. They are designed to most efficiently capture the power of the wind, with as little excess wobbling as possible. A modern wind power generator is usually placed at the top of a pillar some 200 to 300 feet (60m to 90m) high, and the blades themselves are between 60 and 130 feet (18m to 40m) long. Most generators have variable speeds, allowing them to best make use of the wind, and they can be manually shut down if wind speeds get too high, to make sure no damage comes to the equipment.
Currently wind power accounts for only about 1% of the world’s total energy generation, or roughly 95 gW. Some countries have invested substantially more in wind energy, however, with nations like Portugal and Spain generating around 10% of their energy needs through wind, Denmark generating roughly a fifth of their energy through wind, and countries like Ireland and Germany generating more than 5% of their energy through wind.