The timing and magnitude of wind turbine installations in the United States are often driven by tax incentives. The U.S. production tax credit (PTC), a per-kilowatthour (kWh) credit for electricity generated by eligible renewable sources, was first enacted in 1992 and has been extended and modified in the years since. At the end of December 2020, Congress extended the PTC at 60% of the full credit amount, or $0.018 per kWh ($18 per megawatthour), for another year through December 31, 2021. In 2020, the credit was 60% of the full credit amount. Under the new PTC legislation, qualifying wind projects must begin construction by December 31, 2021.