A common question is: how many times has the Production Tax Credit (PTC) for wind power production been extended since the original law was enacted in 1992.
The answer is a dirty dozen, which makes the federal lifeline to wind power 28 years old. That’s old age for a government subsidy, particularly one where the industry itself has long proclaimed its impending competitiveness.
“The U.S. wind industry has … demonstrated reliability and performance levels that make them very competitive,” stated a representative of the American Wind Energy Association (AWEA) back in 1986.  And Joe Romm a quarter-century later: “It is clear that solar and wind are competitive in many situations right now.” 
And so Milton Friedman’s warning that infant industries receiving government protection never seem to grow up has a stellar example.  Below, I try to get the laws and dates right to account for the twelve extensions, relying in particular on two documents: the Renewable Electricity Production Tax Credit (CRS: November 27, 2018) and United States Wind Energy Policy (Wiki).
The Energy Policy Act of 1992 (P.L. 102-486) enacted the renewable electricity production tax credit at $0.015/kWh, adjusted for inflation. Available for new projects beginning in 1993 for ten years, the provision was set to expire July 1, 1999.
Twenty-one years and a dozen extensions later, the tax credit stands at $0.024/kWh for existing projects. The extensions when new construction could receive the 10-year credit are chronicled below.
 Statement of Michael L.S. Bergey, American Wind Energy Association in Renewable Energy Industries, Hearing before the Subcommittee on Energy Conservation and Power of the Committee on Energy and Commerce, House of Representatives, 99th Cong., 2nd sess. (Washington, D.C.: Government Printing Office, 1986), p. 129. (emphasis added)
 Joe Romm, “Fred Hiatt Back to running Climate and Energy Disinformation from the Likes of Bjorn Lomborg,” ThinkProgress, April 21, 2011.
 “The infant industry argument is a smoke screen. The so-called infants never grow up. Once imposed, tariffs are seldom eliminated.” Milton and Rose Friedman, “The Case for Free Trade,” [1997: 4] Hoover Digest.