; or (II) all electric consumers served by the Independent System Operator, Regional Transmission Organization, or the applicable joint unit commitment and centralized economic dispatch system that serves the retail electricity supplier. (iii) Notification of election A retail electricity supplier shall inform the Secretary of its election under clause (ii) not later than 180 days after the date of enactment of this Act. (C) Minimum percentage of zero-emission electricity The term minimum percentage of zero-emission electricity means, with respect to a retail electricity supplier— (i) for each of calendar years 2022 and 2023, the baseline zero-emission electricity percentage; (ii) for each of calendar years 2024 through 2050, the amount, not to exceed 100 percent, obtained by adding— (I) the minimum percentage of zero-emission electricity for the previous calendar year; and (II) the annual percentage increase; and (iii) for each calendar year after 2050, 100 percent. (b) Reporting on behind-the-Meter generation systems Effective beginning in calendar year 2022, each retail electricity supplier serving one or more behind-the-meter generation systems may, not later than January 1 of each calendar year, submit to the Secretary— (1) verification of the carbon intensity of behind-the-meter generation systems connected to the retail electricity supplier