The number of ERCs each NGCC can produce is based on a complex combination of factors, including how much better the NGCC
unit's emission rate is compared to the national
fossil steam emission performance rate, the distribution of the total possible incremental
generation across all NGCC
units, and the total net energy output from the NGCC
unit in the year for which ERCs are being calculated.
The state - level emissions performance goals under the proposed Clean Power Plan are not based on a simple emission rate calculation (emissions divided by
generation) for
generation provided by existing
fossil - fired electric generating
units.