; by (B) the extent to which the operation of the generating unit results in fewer greenhouse gas emissions than an efficient coal-burning power plant, which is the number that equals— (i) 1.0; less (ii) the quotient obtained by dividing— (I) the carbon intensity of the generating unit; by (II) the carbon intensity of an efficient coal-burning power plant (which is 0.82 metric tons of carbon dioxide per megawatt-hour). (22) Zero-emission electricity credit The term zero-emission electricity credit means a credit issued pursuant to section 204. 202. Zero-emission electricity requirement (a) Zero-Emission electricity requirement (1) Credit submission requirement Except as otherwise provided in this section, effective beginning with calendar year 2022, for each calendar year, not later than June 1 of the following calendar year, each retail electricity supplier shall submit to the Secretary a quantity of zero-emission electricity credits that is equal to— (A) for each of calendar years 2022 and 2023, the quantity of zero-emission electricity credits determined under paragraph (3) for the retail electricity supplier for such calendar year