; (iii) codes and standards savings of natural gas; and (iv) fuel-switching energy savings that results in net savings of natural gas. (13) Performance standard The term performance standard means a standard— (A) established for a calendar year for cumulative electricity savings or cumulative natural gas savings that is expressed as a percentage of base quantity; and (B) for each of calendar years 2021 through 2035, that is labeled as cumulative electricity savings percentage or cumulative natural gas savings, as applicable, in the table under subsection (c)(2). (14) Power pool The term power pool means an association of two or more interconnected electric systems that have entered into an agreement to coordinate operations and planning for improved reliability and efficiencies, including a Regional Transmission Organization or an Independent System Operator, as determined by the Secretary. (15) Reporting period The term reporting period means— (A) calendar years 2021 through 2023; and (B) each successive 2-calendar-year period thereafter. (16) Retail electricity supplier (A) In general The term retail electricity supplier means, for any calendar year, an electric utility that delivered not fewer than 1,000,000 megawatt hours of electricity to electric consumers for purposes other than resale during the preceding calendar year. (B) Inclusions and limitations For purposes of determining whether an electric utility qualifies as a retail electricity supplier under subparagraph (A)— (i) deliveries by any affiliate of the electric utility to electric consumers for purposes other than resale shall be considered to be deliveries by the electric utility