History of wind power

This article is about the history of wind power.

Early history

Sailboats and sailing ships have been using wind power for at least 5,500 years, and architects have used wind-driven natural ventilation in buildings since similarly ancient times. The use of wind to provide mechanical power came somewhat later in antiquity.

Early examples of wind power machines were used in Persia as early as 200 BC, and were introduced into the Roman Empire by 250 AD. However, the first practical windmills were built in Sistan, Afghanistan, from the 7th century. These were vertical axle windmills, which had long vertical driveshafts with rectangle shaped blades. Made of six to twelve sails covered in reed matting or cloth material, these windmills were used to grind corn and draw up water, and were used in the gristmilling and sugarcane industries.

12th century A.D.

The first horizontal axle windmills in Europe were recorded. These would have been post mills. One such was constructed in 1137 at Leicester. While English crusaders may have seen the windmills of the Mid-East, the horizontal-axis post mills are of significantly different design than those in Sistan. In England at the time, rights to waterpower sites were confined to nobility and clergy, so wind power was an important resource to a new middle class.

14th century A.D.

By the 14th century Dutch windmills were in use to drain areas of the Rhine River delta.

19th century A.D.

In Denmark by 1900 there were about 2500 windmills for mechanical loads such as pumps and mills, producing an estimated combined peak power of about 30 MW.

In the American midwest between 1850 and 1900, a large number, perhaps six million, small windmills were installed on farms to operate irrigation pumps.

The first windmill for electricity production was built in Scotland in July 1887 by Prof James Blyth of Anderson's College, Glasgow (the precursor of Strathclyde University.

Across the Atlantic, in Cleveland, Ohio a larger and heavily engineered machine was designed and constructed in 1887-1888 by Charles F. Brush, this was built by his engineering company at his home and operated from 1886 until 1900. The Brush wind turbine had a rotor 56 feet (17 m) in diameter and was mounted on a 60 foot (18 m) tower. Although large by today's standards, the machine was only rated at 12 kW; it turned relatively slowly since it had 144 blades. The connected dynamo was used either 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 fell into disuse after 1900 when electricity became available from Cleveland's central stations, and was abandoned in 1908.

20th century A.D.

In Denmark wind power was an important part of a decentralized electrification in the first quarter of the 20th century, partly because of the Danish wind power scientist Poul la Cour from his first practical development in 1891 at Askov. In 1956 Johannes Juul installed a 24 m diameter wind turbine at Gedser, which ran from 1956 until 1967. This was a three-bladed, horizontal-axis, upwind, stall-regulated turbine similar to those now used for commercial wind power development.

In 1927 the brothers Joe Jacobs and Marcellus Jacobs opened a factory in Minneapolis to produce wind turbine generators for farm use. These would typically be used for lighting or battery charging, on farms out of reach of sentral-station electricity and distribution lines. In 30 years the firm produced about 30,000 small wind turbines, some of which ran for many years in remote locations in Africa and on the Byrd expedition to Antarctica. Many other manufacturers produced small wind turbine sets for the same market, including companies called Wincharger, Miller Airlite, Universal Aeroelectric, Paris-Dunn, Airline and Winpower.

1931: The darrieus wind turbine is invented. Turbines no longer have to be turned into the wind, and the axle can be one and the same as the tower.

By the 1930s windmills were widely used to generate electricity on farms in the United States where distribution systems had not yet been installed. Used to replenish battery storage banks, these machines typically had generating capacities of a few hundred watts to several kilowatts. Beside providing farm power, they were also used for isolated applications such as electrifying bridge structures to prevent corrosion. In this period, high tensile steel was cheap, and windmills were placed atop prefabricated open steel lattice towers.

The most widely-used small wind generator produced for American farms in the 1930s was a two-bladed horizontal-axis machine manufactured by the Wincharger Corporation. It had a peak output of 200 watts. Blade speed was regulated by curved air brakes near the hub that deployed at excessive rotational velocities. These machines were still being manufactured in the United States during the 1980s. In 1936, the U.S. started a rural electrification project that killed the natural market for wind-generated power, since network power distribution provided a farm with more dependable usable energy for a given amount of capital investment.

A forerunner of modern horizontal-axis wind generators was in service at Yalta, USSR in 1931. This was a 100 kW generator on a 30 m (100 ft) tower, connected to the local 6.3 kV distribution system. It was reported to have an annual load factor of 32 per cent, not much different from current wind machines.

The world's first megawatt-size wind turbine on Grandpa's Knob, Castleton, Vermont

In 1941 the world's first megawatt-size wind turbine was connected to the local electrical distribution system on Grandpa's Knob in Castleton, Vermont, USA. It was designed by Palmer Cosslett Putnam and manufacturered by the S. Morgan Smith Company. This 1.25 MW Smith-Putnam turbine operated for 1100 hours before a blade failed at a known weak point, which had not been reinforced due to war-time material shortages.

During the Second World War, small wind generators were used on German U-boats to recharge submarine batteries as a fuel-conserving measure.

In Australia, the Dunlite Corporation built hundreds of small wind generators to provide power at isolated postal service stations. Manufacture of these machines persisted into the 1970s.

In the 1970s many people began to desire a self-sufficient life-style. Solar cells were too expensive for small-scale electrical generation, so some turned to windmills. At first they built ad-hoc designs using wood and automobile parts. Most people discovered that a reliable wind generator is a moderately complex engineering project, well beyond the ability of most romantics. Some began to search for and rebuild farm wind generators from the 1930s, of which Jacobs Wind Electric Company machines were especially sought after. Hundreds of Jacobs machines were reconditioned and sold during the 1970s.

The NASA/DOE 7.5 megawatt Mod-2 three turbine cluster in Goodnoe Hills, Washington in 1981

From the mid 1970's through the mid 1980's the United States government worked with industry to advance the technology and enable large commercial wind turbines. This effort was led by NASA at the Lewis Research Center in Cleveland, Ohio and was an extraordinarily successful government research and development activity. With funding from the National Science Foundation and later the Department of Energy (DOE), a total of 13 experimental wind turbines were put into operation including four major wind turbine designs. This research and development program pioneered many of the multi-megawatt turbine technologies in use today, including: steel tube towers, variable-speed generators, composite blade materials, partial-span pitch control, as well as aerodynamic, structural, and acoustic engineering design capabilities. The large wind turbines developed under this effort set several world records for diameter and power output. The Mod-2 wind turbine cluster produced a total of 7.5 megawatt of power in 1981. In 1987, the Mod-5B was the largest single wind turbine operating in the world with a rotor diameter of nearly 100 meters and a rated power of 3.2 megawatts. It demonstrated an availability of 95 percent, an unparalleled level for a new first-unit wind turbine. The Mod-5B had the first large-scale variable speed drive train and a sectioned, two-blade rotor that enabled easy transport of the blades.

Following experience with reconditioned 1930s wind turbines, a new generation of American manufacturers started building and selling small wind turbines not only for battery-charging but also for interconnection to electricity networks. An early example would be Enertech Corporation of Norwich, Vermont, which began building 1.8 kW models in the early 1980s.

Later, in the 1980s, California provided tax rebates for ecologically harmless power. These rebates funded the first major use of wind power for utility electricity. These machines, gathered in large wind parks such as at Altamont Pass would be considered small and un-economic by modern wind power development standards.

In the 1990s, as aesthetics and durability became more important, turbines were placed atop steel or reinforced concrete towers. Small generators are connected to the tower on the ground, then the tower is raised into position. Larger generators are hoisted into position atop the tower and there is a ladder or staircase inside the tower to allow technicians to reach and maintain the generator.

Originally wind generators were built right next to where their power was needed. With the availability of long distance electric power transmission, wind generators are now often on wind farms in windy locations and huge ones are being built offshore, sometimes transmitting power back to land using high voltage submarine cable. Since wind turbines are a renewable means of generating electricity, they are being widely deployed, but their cost is often subsidised by taxpayers, either directly or through renewable energy credits. (By comparison, fossil fuels also may receive direct subsidies, along with indirect subsidies in the form of taxpayer support for external costs such as disability payments for coal miners, pollution which can increase health care costs, military spending to protect oilfields, etc.) Much depends on the cost of alternative sources of electricity, and on whether governments choose to internalize the external costs of various energy sources by taxing their consumption. Wind generator cost per unit power has been decreasing by about four percent per year, due largely to improved technology, the accumulating experience of wind farm operators, and the trend toward ever-larger wind turbines. In the meantime, fossil fuel costs have tended to increase, especially for petroleum and natural gas.

21st century A.D.

As the 21st century began, fossil fuel was still relatively cheap, but rising concerns over energy security, global warming, and eventual fossil fuel depletion led to an expansion of interest in all available forms of renewable energy. The fledgling commercial wind power industry began expanding at a robust growth rate of about 30% per year, driven by the ready availability of large wind resources, and falling costs due to improved technology and wind farm management. The steady run-up in oil prices after 2003 led to increasing fears that peak oil was imminent, further increasing interest in commercial wind power. Even though wind power generates electricity rather than liquid fuels, and thus is not an immediate substitute for petroleum in most applications (especially transport), fears over petroleum shortages only added to the urgency to expand wind power. Earlier oil shocks had already caused many utility and industrial users of petroleum to shift to coal or natural gas. Natural gas began having its own supply problems, and wind power showed potential for replacing natural gas in electricity generation.

2001:Enron, owner of Enron Wind Power Services (wind turbine manufacturing and wind farm operation), goes bankrupt in one of the biggest and most complex bankruptcy cases in U.S. history. (see: Enron scandal)

2006: US$10,000 home unit can generate 80% of a typical home's needs

2007: Shawn Frayne wins the 2007 Popular Mechanics Breakthrough Award for the Windbelt, a non-turbine wind power generator that produces power at 1/10 the price per watt as turbines.