property Section 48(c)(4)(C) of such Code is amended by striking for any period after December 31, 2016 and inserting the construction of which does not begin before January 1, 2022 . (f) Thermal energy property Section 48(a)(3)(A)(vii) of such Code is amended by striking periods ending before January 1, 2017 and inserting property the construction of which begins before January 1, 2022 . (g) Phaseout of 30 percent credit rate for fuel cell and small wind energy property Subsection (a) of section 48 of such Code is amended by adding at the end the following new paragraph: (7) Phaseout for qualified fuel cell property and qualified small wind energy property In the case of qualified fuel cell property or qualified small wind energy property, the construction of which begins before January 1, 2022, the energy percentage determined under paragraph (2) shall be equal to— (A) in the case of any property the construction of which begins after December 31, 2019, and before January 1, 2021, 26 percent, and (B) in the case of any property the construction of which begins after December 31, 2020, and before January 1, 2022, 22 per-cent. . (h) Phaseout for Fiber-Optic Solar Energy Property Section 48(a)(6) of such Code is amended by inserting or (3)(A)(ii) after paragraph (3)(A)(i) . (i) Effective date The amendments made by this section shall take effect on the date of the enactment of this Act.