How many GHGs does a light bulb emit? GHG emissions associated with electricity consumption

Abstract

Greenhouse gases (GHGs) associated with electricity consumption are regularly included in GHG reporting protocols. Canadian examples are used to illustrate where issues arise and where there is room for improvement, specifically the electricity emission factor (EEF). The EEF is affected by a number of factors including: Uncertainty of GHG emissions; GHG accounting; and Grid supply mix. Fluctuation in fuel quality can affect overall CO2 emissions and the EEF. An internal study conducted by Environment Canada found that emissions data reported via stack-specific continuous emissions monitoring systems differed by between 2 and 6% from those developed using generic emission factors and fuel consumption data. The GHG accounting for Canada's EEFs includes combus- tion emissions only, excluding process or fugitive emissions and emissions associated with the transportation and distribution of elec- tricity. The variability in the grid supply mix also has an impact on GHG emissions due to contributions by different types of generators. The supply of electricity in Ontario during typical work hours is compared to a 24-hour average, showing that coal fired generation provides a greater percentage of electricity between 8 a.m. and 5 p.m. than over a 24-hour period. The dynamic nature of the electricity supply, uncertainty and variability in generating facility GHG emissions and improvements in GHG accounting are all areas where there is room for improvement.