Post 1970s Wind Energy
Interest in harnessing energy from renewable sources such as wind received a fillip in the aftermath of the OPEC oil embargo of the 1970s. The subsequent increase in energy prices, the expense of replacing electric pumps and the growing environmental awareness sustained further advancements in windmill technology.
NASA, with funding from the National Science Foundation and the United States Department of Energy (DOE) took the lead in advancing technology and developing large commercial wind turbines.
The association of NASA and windmills is a watershed in the history of wind energy. NASA's research enhanced the aerodynamic, structural, and acoustic engineering design capabilities of windmills and incorporated steel tube towers, variable-speed generators, composite blade materials, and partial-span pitch control in windmill technology. These features contributed to many-fold increase in power generating capabilities of individual windmills. NASA’s MOD-2 wind turbine cluster produced a total of 7.5 megawatt of power in 1981 and MOD-5B, the largest single wind turbine operating in the world with a rotor diameter of nearly 100 meters had a rated power of 3.2 megawatts.
By 2006, the wind turbines across the US generated 26.6 KWh of electricity, sufficient to power 2.4 million homes. In 2008, Rock Port, Missouri became the first city in the United States to receive its entire power requirements from wind energy.