By Annie Levasseur

Annie Levasseur | École de Technologie Supérieur

Canadian hydropower is one of the lowest-emission energy generating options on the planet. This statement is not based on interpretation or extrapolation. It is based on science rigorously developed over decades by independent researchers, including myself. Science that is regularly updated as through my own study published this year.  

RTO Insider recently published an inflammatory article in which the claim is made that “scientists say Canadian hydropower is not clean” and that Canadian hydropower’s carbon emissions levels compare unfavorably to those of natural gas and even coal-based generation. (See Scientists, First Nations Say Hydropower is Not Clean Energy.)

This is completely inconsistent with the preponderance of scientific evidence.

The study of greenhouse gas emissions from Québec hydroelectric reservoirs began in the early ‘90s, and these studies show that emissions peak immediately after reservoir creation and decline to natural lake levels within about ten years.

Greenhouse gas emissions from any energy source is expressed in gCO₂-eq/kWh, which represents the amount of GHG emitted per unit of energy produced. For hydropower, the intensity varies according to multiple factors, such as temperature, the density of vegetation flooded, powerhouse energy output, etc. Biological and climatic conditions that prevail in a cold boreal climate such as Québec result in a mean value of 34 gCO₂-eq/kWh for Hydro-Québec’s generating fleet (Levasseur et al., 2021). This is low compared to coal power plants, with mean values higher than 875 gCO₂-eq/kWh.

Additionally, reporter E. Hayes points to scientific studies to support her claims but she does so erroneously. For example, she is using a specific high value of emissions taken from Scherer and Pfister (2016) that is the result of modelling data from the Hertwich (2013) model without any model validation and calibration with field data. Comparing Churchill Falls, situated in cold Canadian boreal zone, to natural gas is incorrect. Bastien et al. 2009 has clearly showed that GHG emissions from that reservoir were very low and similar to surrounding lakes. Similar field values are also observed on Caniapiscau and Laforge reservoirs (Québec) sharing similar biological, climatic and geological characteristics (Tremblay et al., 2005). The reporter should get her facts right.

We are faced with a global climate crisis. Our society must reduce its carbon footprint and move toward lower-emitting sources. Hydropower generated in Québec is one of those sources. Misinformation will not help us make the right decisions on climate change, but taking bold actions like collaborating across the border to bring clean sustainably developed energy will. 

Annie Levasseur is Professor, École de technologie supérieure, Montréal, Canada and Chairholder of the Canada Research Chair on Measuring the Impact of Human Activities on Climate Change.
 
 Levasseur and her co-authors said their study earlier this year “did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sector.

“The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported” in the paper, they added.
 

References

Hertwich, E.G., 2013. Addressing Biogenic Greenhouse Gas Emissions from Hydropower in LCA. Environmental Science and Technology, 47, 9604-9611. Dx.doi.org/10.1021/es401820p.

Bastien, J., A. Tremblay & L. LeDrew, 2009. Greenhouse Gases Fluxes from Smallwood Reservoir and natural water bodies in Labrador, Newfoundland, Canada. Verh. Internat. Verein. Limnol.   Vol 30, Part 6, p. 858-861.

Levasseur, A., S. Mercier-Blais, Y.T. Prairie, A. Tremblay & C. Trpin, 2021. Improving the accuracy of electricity carbon footprint: estimation of hydroelectric reservoir greenhouse gas emissions. Renewable & Sustainable Energy Reviews, 136. https://doi.org/10.1016/j.rser.2020.110433.

Tremblay, A., L. Varfalvy, C. Roehm & M. Garneau, (Eds.), 2005. Greenhouse Gas Emissions: Fluxes and Processes, Hydroelectric Reservoirs and Natural Environments. Environmental Science Series, Springer, Berlin, Heidelberg, New York, 732 pages