qualified cogeneration facility that would emit a lesser quantity of greenhouse gases per megawatt hour of electricity or per million British thermal units of useful thermal energy output, as applicable, than the Administrator distributes to covered entities under subsection (a), (b), or (c), as applicable, in the first full calendar year during which the newly constructed facility operates and is a party to an agreement described in paragraph (2). (4) Distribution of allowances to an existing facility (A) In general For calendar years that are covered by an agreement described in paragraph (2), beginning with the first full calendar year during which the newly constructed low-emission facility operates, the Administrator shall distribute, on a continual basis, to the existing facility— (i) for megawatt hours of electricity or million British thermal units of useful thermal energy output, as applicable, produced by the existing facility that are covered by the agreement, a number of emission allowances that is equal to— (I) such number of megawatt hours or million British thermal units, as applicable