Energir mandated the CIRAIG’s International Life Cycle Chair to use life cycle assessment (LCA) methodology to assess the environmental impacts of i) its distributed natural gas, ii) compare these environmental impacts with the ones from oil products, and iii) quantify the potential decrease of environmental impacts associated with a change of supplies.
The main conclusions from this report are:
- Natural gas fugitive emissions assessment has evolved since 2010: starting from studies with several assumptions and limited data (2010-2012), moving through on-site measurements (2012-2015) and atmospheric concentration measurements (2012-2015), to the controversy about the last two approaches providing wildly different results (while they should provide the same), and the reconciliation between both on-site and atmospheric concentration measurements (2016-). The literature average’s life cycle fugitive assessment is currently assessed between 1 and 2%.
- Due to significantly lower fugitive emission in its distribution network (0.04%) than reported in the literature (0.22%), the average fugitive emission of the natural distributed in Quebec is estimated at 0.93%.
- Energir’s distributed natural gas resulted in 32% less GHG emissions than fuel oil for heating, 16% less than diesel for heavy transport, and 23% less than heavy fuel oil for marine transport.
- The GHG emission of the natural gas supply could be decrease by 32% if 100% of the supply came from initiatives which limits their fugitive emissions (0.5% instead of 0.93%).
- Renewable natural gas (RNG) has the potential to be carbo-negative with the “recycling of the organic matter” which avoids more GHG emissions (e. g. no methane emission at the landfill, decrease emission from the production of chemical fertilizers, etc.) than generated by the RNG production.