US Census Bureau Throughout the decades since the oil embargo of 1973, increasing research and development has gone into renewable sources of energy. Some of the results are seen atop windswept hills and plains across America — large electricity generating windmills. While the concept sounds very modern, the first practical wind turbine generator goes back 74 years. According to the US Census, it was on this October 19 in 1941 that Palmer PutnamofVermontdemonstrated his device. His wind turbine had blades 66 feet in length, and in over 700 hours of operation, produced almost 300,000-kilowatt hours. In the U.S. today, there are over 2,700 electric power generating establishments producing 4.1 million megawatt hours. Wind power provides about 4.5 percent of the country's electricity production.