Québec’s enviable record
While all electricity generation creates GHG emissions, whether directly or indirectly, hydropower ranks as one of the lowest-emission generating options per kilowatthour produced. A hydropower plant with a reservoir in a northern area emits 10 grams of carbon dioxide (CO2) per kilowatthour produced, the same quantity as wind power. Solar power, generated via photovoltaic panels, emits four times more GHGs, and a coal-fired power plant produces 100 times more GHG emissions than a hydropower plant
Because more than 99% of its power is generated by renewables (counting all producers), Québec’s GHG emissions were in 2011 the lowest in Canada, at 10 metric tons per capita.
The electricity sector accounted for less than 1 % of Québec’s GHG emissions in 2011, compared with 45% (36 Mt) for the transportation sector. Hydroelectricity generated in Quebec in 2011 accounted for 51% of all hydroelectricity generated in Canada, and 32% of the total electricity generated overall; however, it represented less than 1 % of the GHG emissions from Canadian electric utilities.
GHGs and reservoirs: Low emissionsAll natural aquatic areas emit greenhouse gases. Similarly, Hydro-Québec’s northern reservoirs emit small quantities of GHGs.
The flooding of large areas of land leads to an increase in GHG emissions, but this is a temporary phenomenon. Generally speaking, emissions from northern reservoirs return to the level observed in natural lakes within 10 years.
The main gas emitted by northern reservoirs is carbon dioxide (CO2). They also give off methane (CH4), but in minute quantities since the cold, well-oxygenated waters of Québec’s large water bodies are not conducive to the formation of this gas. Consequently, methane emissions are not an issue for large hydro in Québec.
Greenhouse gas production and hydroelectric reservoir
A large-scale scientific study was carried out in collaboration with 80 experts from Université du Québec à Montréal, McGill University and Environnement Illimité Inc.from 2003 to 2009. Results now show that, of all generation methods, hydropower boasts one of the lowest greenhouse gas emissions.
Launched in 2003, the study’s goal was to measure net emissions of greenhouse gases (GHG) at Eastmain 1 reservoir. Some 100,000 scientific facts were analyzed for this unique research program which not only measured GHG emissions after impoundment, but also those of the natural environment prior to the reservoir’s creation.
The findings at the Eastmain 1 reservoir are complimentary to those concerning the life cycle of various means of electricity generation. They confirm that GHG emissions for average Hydro-Québec reservoirs are similar to those from wind power.