; and (ii) estimate the impact of the standards on current and future electricity and natural gas use in the service territories of the suppliers; (C) by establishing requirements governing applications for, and implementation of, delegated State administration under subsection (f); and (D) by establishing rules to govern transfers of electricity or natural gas savings— (i) between suppliers and third-party efficiency providers serving the same State; and (ii) between suppliers and third-party efficiency providers serving different States. (2) National Academy of Sciences study In establishing and implementing this section, the Secretary shall take into consideration a report published under subsection (d)(2)(C). (3) Coordination with State programs In establishing and implementing this section, the Secretary shall, to the maximum extent practicable, preserve the integrity and incorporate best practices of existing State energy efficiency programs. (4) Savings programs for low-income customers In implementing this section, the Secretary shall encourage retail electricity suppliers and retail natural gas suppliers to ensure that a portion of the customer facility savings achieved for a calendar year shall result from programs that target households that are at or below 200 percent of the poverty line (as defined in section 673 of the Community Services Block Grant Act ( 42 U.S.C. 9902 )). (c) Performance standards (1) Compliance obligation Not later than May 1 of the calendar year immediately following each reporting period— (A) each retail electricity supplier shall submit to the Secretary a report, in accordance with regulations promulgated by the Secretary, demonstrating that the retail electricity supplier has achieved cumulative consistent electricity savings (adjusted to account for any attrition of savings measures implemented in prior years) in each calendar year that are equal to the applicable percentage of the base quantity of the retail electricity supplier