generation unit, the basis of such property shall be reduced by the amount of the credit so allowed. (f) Termination This section shall apply to taxable years beginning after December 31, 2017, and ending before January 1, 2023. . (b) Assessment by Federal Energy Regulatory Commission (1) In general In the case of any coal-powered electric generation unit which has claimed a credit under section 45T of the Internal Revenue Code of 1986 (as added by subsection (a)), the Federal Energy Regulatory Commission shall require the applicable reliability coordinator to conduct an assessment analyzing the reliability and resilience attributes offered by such unit to the regional grid in which it is located, with such assessment to be completed not later than April 1, 2023. (2) Reporting Not later than June 1, 2023, the Federal Energy Regulatory Commission shall report to the relevant Congressional committees— (A) the results of the assessments described under paragraph (1)