increase, and modifications of nonbusiness energy property credit (a) Extension of credit Section 25C(g)(2) is amended by striking December 31, 2020 and inserting December 31, 2025 . (b) Increase in credit percentage for qualified energy efficiency improvements Section 25C(a)(1) is amended by striking 10 percent and inserting 15 percent . (c) Increase in lifetime limitation of credit Section 25C(b)(1) is amended— (1) by striking $500 and inserting $1,200 , and (2) by striking December 31, 2005 and inserting December 31, 2020 . (d) Limitations Section 25C(b) is amended by striking paragraphs (2) and (3) and inserting the following: (2) Limitation on qualified energy efficiency improvements The credit allowed under this section by reason of subsection (a)(1), with respect to costs paid or incurred by a taxpayer for a taxable year, shall not exceed— (A) for components described in subsection (c)(3)(A), the excess (if any) of $600 over the aggregate credits allowed under this section with respect to such components for all prior taxable years ending after December 31, 2020, (B) for components described in subsection (c)(3)(B), (i) in the case of components which are not described in clause (ii), the excess (if any) of $200 over the aggregate credits allowed under this section with respect to such components for all prior taxable years ending after December 31, 2020, and (ii) in the case of components which meet the standards for most efficient certification under applicable Energy Star program requirements, the excess (if any) of $600 over the aggregate credits allowed under this section with respect to such components for all prior taxable years ending after December 31, 2020, or with respect to components described in clause (i) for such taxable year, and (C) for components described in subsection (c)(3)(C) by any taxpayer for any taxable year, the credit allowed under this section with respect to such amounts for such year shall not exceed the lesser of— (i) the excess (if any) of $500 over the aggregate credits