How is coal seam methane gas treated, as opposed to waste coal mine gas, within GGAS?
Under GGAS, coal seam methane and waste coal mine gas are treated differently when used as fuel for generation activities, although their geological genesis is identical. The reason for this different treatment stems from the fact that coal seam methane gas per se would be geologically ‘locked-up’ if not for its extraction and production. As such it is treated as natural gas and creates abatement certificates on the basis of its lower emissions intensity (when compared to that of the NSW pool coefficient). On the other hand, coal seam methane which is liberated from geological ‘enclosure’ as a function of mining activity is seen to be a fugitive greenhouse emission, if not for its capture and combustion in the form of waste coal mine gas. As such, waste coal mine gas receives an additional benefit (in terms of the number of abatement certificates created per MWh of generation) in recognition of the fugitive methane emissions avoided (methane having a global warming potential 21 times t
