| Early 1900s to 1950 | Early wind power in the United States | Windmills were used to pump water and were also used for remote electricity generation. |
| 1941 | First grid-connected electricity | On a hilltop in Rutland, Vermont, "Grandpa's Knob" wind generator supplied power to the local grid for several months during World War II. The Smith- Putnam machine was rated at 1.25 megawatts in winds of about 30 miles per hour. It was removed fromservice in 1945. |
| 1973 | OPEC oil embargo | Oil and gas prices rose, increasing interest in alternative energy sources. |
| 1974-1975 | NASA's MOD-0 developed | The MOD-0, a horizontal axis wind turbine was developed at the NASA Lewis Research Center in Cleveland, Ohio. |
| 1977-1981 | MOD-0, MOD-1, and MOD-2 developed and tested | Four MOD-0As, rated at 200 kilowatts each, were placed at utility sites around the country for tests between 1977 and 1980. The MOD-1, with a 2-megawatt capacity rating, the first wind turbine rated over 1 megawatt, began operating in 1979. |
| 1978 | Public Utility Regulatory Policies Act (PURPA) enacted | PURPA mandated the purchase of electricity from qualifying facilities (QFs) meeting certain technical standards regarding energy source and efficiency. PURPA also exempted QFs from both State and Federal regulation under the Federal Power Act and the Public Utility Holding Company Act. |
| 1979 | Federal funding for wind power research and development (R&D) exceeds $50 million | U.S. Department of Energy (DOE) funding for wind power R&D was $59.6 million in fiscal year 1978 (current year dollars), marking the first time the funding level surpassed $50 million. It remained above $50 million until fiscal year 1982, when it was reduced to $16.6 million (current year dollars). |
| 1980 | Crude Oil WindfallProfits Tax Act | The Act increased the business energy tax credit to 15 percent. Combined with an investment tax credit passed earlier, the total Federal tax credit for a wind turbine was 25 percent. In addition, California had a 25- percent State tax credit in the early 1980s, bringing the effective tax credit to nearly 50 percent. |
| 1983 | Interim Standard Offer Number 4 (ISO4) contracts in California | Because of a projected capacity shortfall, California utilities contracted with facilities that qualified under PURPA to generate electricity independently. The ISO4 contracts set a price based on long-run costs avoided by not building the coal plants that had been planned. The contracts, combined with favorable tax incentives mentioned above, encouraged the installation of many hastily designed wind turbines in California in the early 1980s. |
| 1985 | California wind capacity at 1 gigawatt | Most of California's wind capacity, which totaled more than 1,000 megawatts in 1985, was installed on the Tehachapi and Altamont Passes. |
| 1988 | Decline in cumulative wind capacity | Many of the hastily installed turbines of the early 1980s were removed and later replaced with more reliable models. |
| 1989 | Low point in Federal funding for wind power | Throughout the 1980s, DOE funding for wind power R&D declined, reaching its low point in fiscal year 1989. |
| 1990 | California wind capacity in excess of 2 gigawatts | In 1990, more than 2,200 megawatts of wind energy capacity was installed in Californiažmore than half of the worldžs capacity at the time. |
| 1992 | Energy Policy Act | The Act reformed the Public Utility Holding Company Act and many other laws dealing with the electric utility industry. It also authorized a performance tax credit of 1.5 cents per kilowatthour for wind-generated electricity. |
| 1993 | 33M-VS commercially available | The 33M-VS was one of the first commercially available, variable-speed wind turbines. U.S. Windpower developed the 33M-VS over a period of 5 years, with final prototype tests completed in 1992. The $20 million project was funded mostly by U.S. Windpower, but also involved Electric Power Research Institute (EPRI), Pacific Gas & Electric, and Niagara Mohawk Power Company. |
| 1995 | FERC prohibition on QF contracts above avoided cost | In a ruling against the California Public Utility Commission, FERC refused to allow a bidding procedure that would have the effect of allowing rates above avoided cost from renewable QFs. |
| Mid-1990s | ISO4 contract rollover in California at lower rates | Ten-year QF contracts written during the mid-1980s at rates of 6 cents per kilowatthour and higher began rolling over at mid-1990s avoided costs of about 3 cents per kilowatthour. This " 11th-year cliff" creates financial hardship for most QFs on ISO4 contracts. |
| 1995 | DOE wind program lowers technology costs | DOE's advanced turbine program, funded at $49 million, has led to new turbines with energy costs of 5 cents per kilowatthour of electricity generated. |