; (2) at the end of clause (vii) by inserting or ; and (3) by inserting after clause (vii) the following new clause: (viii) open-loop biomass (within the meaning of section 45(c)(3)) heating property, including boilers or furnaces that operate at thermal output efficiencies of not less than 65 percent (measured by the higher heating value of the fuel) and that provide thermal energy in the form of heat, hot water, or steam for space heating, air conditioning, domestic hot water, or industrial process heat, . (b) 30-Percent and 15-Percent credits (1) Energy percentage (A) In general Subparagraph (A) of section 48(a)(2) of the Internal Revenue Code of 1986 is amended by redesignating clause (ii) as clause (iii) and by inserting after clause (i) the following new clause: (ii) except as provided in clause (i)(V), 15 percent in the case of energy property described in paragraph (3)(A)(viii), but only with respect to property the construction of which begins before January 1, 2022, and . (B) Conforming amendment Clause (iii) of section 48(a)(2)(A) of such Code, as so redesignated, is amended by inserting or (ii) after clause (i) . (2) Increased credit for greater efficiency Clause (i) of section 48(a)(2)(A) of such Code is amended by striking and at the end of subclause (III) and by inserting after subclause (IV) the following new subclause: (V) energy property described in paragraph (3)(A)(viii) which operates at a thermal output efficiency of not less than 80 percent (measured by the higher heating value of the fuel), but only with respect to property the construction of which begins before January 1, 2022, . (c) Effective date The amendments made by this section shall apply to periods after December 31, 2016, in taxable years ending after such date, under rules similar to the rules of section 48(m) of the Internal Revenue Code of 1986 (as in effect on the day before the date of the enactment of the Revenue Reconciliation Act of 1990).