Lifecycle greenhouse gas emissions from electricity in the province of Ontario at different temporal resolutions.

In this paper, we model the greenhouse gas (GHG) intensity of the electric grid in Ontario, Canada, at different temporal resolutions from 2010 through 2018. We developed a stochastic approach to estimate the lifecycle GHG emissions from each type of source of electricity, by assigning uncertainties to critical parameters (carbon dioxide (CO 2), methane and nitrous oxide emissions, and global warming potentials (GWP)), based on variations reported in the literature. The annual mean lifecycle GHG emissions from electricity generated in the province has declined from 175 to 58 g CO 2 e/kWh from 2010 to 2018, considering the GWP time horizon of 100 years. The downward trend is largely associated with the phasing out of coal plants, coupled with the gradually reduced use of natural gas plants, and the increased participation of nuclear and renewables in the mix over the years. We were also able to identify large variations in the lifecycle GHG emissions across months and hours: higher values are generally associated with demand peaks registered in the months of summer and winter, and daily from 5 to 8 p.m. The method employed for the analysis in this paper can serve as a benchmark for other studies on the lifecycle GHG emissions from electricity at various levels (national, provincial, regional, etc.). The Ontario-specific data obtained can serve as a basis for the evaluation of the lifecycle of various activities and sectors within the province. At the corporate level, companies reporting the GHG emissions of their projects and products can improve their estimates by capturing the variations of emissions from electricity generation at the various temporal resolutions. Image 1 • We used hourly generation data to model GHG intensity of electricity in Ontario. • Emissions from electricity declined from 175 to 58 g CO 2 e/kWh from 2010 to 2018. • Higher emissions are due to demand peaks: summer and winter, daily from 5 to 8 p.m. • Hourly GHG intensity varies by a factor of 4–5 within a single year. • Data obtained are useful for LCA practitioners, policy makers and companies. [ABSTRACT FROM AUTHOR]