7 Scope of Wind Energy Generation Technologies

The energy from the wind has been harnessed since early recorded history all across the world. There are proofs that wind energy propelled boats along the Nile River around 5000 B.C. The use of wind to provide mechanical power came somewhat later in time — by 200 B.C. simple windmills started pumping water in China, and vertical-axis windmills with woven reed sails were grinding grain in the Middle East. The Europeans got the idea of using wind power from the Persians who introduced it to the Roman Empire by 250 A.D. By the 11th century, a strong focus on technical improvements enabled wind power to be leveraged by the people in the Middle East extensively for food production. Returning merchants and crusaders carried this idea back to Europe where the Dutch refined the windmill and adapted it for draining lakes and marshes in 1300s.

In the late 19th century settlers in America began using windmills to pump water for farms and ranches, and later, to generate electricity for homes and industry applications. Although the industrial revolution influenced the propagation of wind energy, larger wind turbines generating electricity continued to appear. The first one was built in Scotland in 1887 by prof. James Blyth from Glasgow. Blyth's 33-ft. tall, cloth-sailed wind turbine was installed in the garden of his holiday home and was used to charge accumulators that powered the lights, thus making it the first house in the world to have its wind power supplied electricity. At the same time across the Atlantic, in Cleveland, Ohio, a larger and heavily engineered machine was constructed in 1888 by Charles F. Brush. His wind turbine had a rotor 17 m in diameter and was mounted on an 18-m tower. Although relatively large, the machine was only rated at 12 kW. The connected dynamo had the ability to charge a bank of batteries or to operate up to 100 incandescent light bulbs, three arc lamps, and various motors in Brush's laboratory. The machine was decomissioned soon after the turn of the century. In the 1940s, the largest wind turbine of the time began operating on a Vermont hilltop known as Grandpa's Knob. This turbine, rated at 1.25 MW fed electric power to the local utility network for several months during World War II.

In Denmark, wind power has played an important role since the first quarter of the 20th century, partly because of Poul la Cour who constructed wind turbines. In 1956, a 24-m diameter wind turbine had been installed at Gedser, where it ran until 1967. This was a three-bladed, horizontal-axis, upwind, stall-regulated turbine similar to those used through the 1980s and into the 1990s for commercial wind energy development, see Fig. 7.1. The popularity of using the wind energy has always fluctuated with the price of fossil fuels. When fuel prices fell in the late 1940s, interest in wind turbines decreased, but when the price of oil skyrocketed in the 1970s, so did worldwide interest in wind turbine generators.