Canada’s plans for radically reducing greenhouse gas emissions by 2050 submitted to the United Nations envisage a complete clean-up of electricity and an electrification of most processes that require fossil fuel combustion. To do this, a mammoth increase in non-emitting electricity generation, primarily from hydro, will be required.

Environment minister Catherine McKenna unveiled Canada’s “Mid-Century Strategy” alongside her US and Mexico counterparts last week during UN climate talks in Marrakech, Morocco, as they released their own 2050 schemes.

‘Not a blueprint’ but a series of options exploring how to achieve an 80 percent net reduction in emissions by 2050

The 87-page Canadian document stresses that it is “not a blueprint” but rather a series of modelled scenarios exploring how to achieve an 80 percent net reduction in emissions by 2050 on 2005 levels. Some 65 percent will be achieved domestically and the remaining 15 percent via a form of international offsets.

Additional electricity will be needed to power transport, buildings and those industrial processes that can switch away from fossil fuel combustion. The total increase in electricity generation required compared to a 2013 reference year ranges in the different scenarios from 189 percent at the lower end up to as high as 295 percent.

Across all scenarios, the heavy lifting here is provided by hydropower, which would see an increase in generation of between 120 and 172 percent, and to a lesser but still substantial extent by nuclear. One scenario reverses the main role though, envisaging a greater presence of nuclear than hydro.

The scenarios involve different energy mixes, with varying roles for other non-emitting sources such as wind, solar and geothermal as well as fossil fuels with carbon capture and storage. They also all include varying amounts of ‘demand response’—a form of energy conservation via voluntary electricity rationing that involves price incentives and technology such as smart metering to reduce consumption.

Hydro’s role can be reduced if nuclear steps up, or vice versa. The central role played by these two energy sources is due to their ability to provide ‘always-on’ electricity. All scenarios involved hydro expansion below the surveyed potential for hydro in Canada, according to the document. A high-nuclear scenario requires the least amount of hydro while a high-hydro scenario requires almost the maximum Canada can build, with a high-conservation scenario not far behind.

An increased role for hydro however does allow for more integration of variable renewables such as wind and solar than nuclear is able to help integrate. This is because hydro reservoirs can be used as energy storage facilities. Of these variable renewable sources, wind achieves much greater penetration than solar in all scenarios.

While some new construction would be needed, the document concludes that much of the hydropower expansion could be accomplished by technologies such as increased-efficiency turbines at existing dams. However, the paper acknowledges that further technological innovation will be required for hydropower to increase substantially. The document also concedes that hydro may have negative environmental implications for fisheries and water flows, and suggests that construction of future large hydro projects will therefore require careful consultation processes.