After the initial legislation expired after 1999, the PTC was allowed to lapse for a year, as it was again after 2001 and 2003. As the wind industry lobby has noted, wind development dropped precipitously in years when the PTC was not available to help energy companies avoid taxes.<ref>American Wind Energy Association. 2015. “Wind Energy and the PTC”.</ref><ref>https://docs.wind-watch.org/schleede-big-money.pdf</ref>
In 2015, legislation ended the PTC for non-wind renewables after 2016 and established a phase-out for wind. Facilities claiming the PTC in 2017 will get 80% of its value, in 2018 60%, and in 2019 40%. After 2019, new facilities can not claim the PTC.
==Investment tax credit==