A very public fight between high-profile researchers over whether the United States economy can run on renewable energy without baseload assistance from nuclear has worrying implications for Canada.
In June, a peer-reviewed analysis by 21 climate and energy ‘rock-star’ scientists appeared in the prestigious Proceedings of the National Academies of Sciences sharply criticising an earlier edition’s 2015 paper from Stanford environmental engineer Mark Jacobson and his colleagues that has been widely cited by US policy-makers and media. That paper claimed a 100 percent-renewables energy system—with no role for bioenergy, nuclear power or carbon capture and storage—is not just feasible but cheaper than the current fossil-dominated system by 2050.
To overcome the reliability challenge of electricity grids from variable sources such as wind and solar, Jacobson’s modelling depends upon two main elements: a colossal build-out of energy storage and an equally mammoth expansion of hydroelectric capacity. More specifically, such a system would require a massive deployment of underground thermal energy storage (UTES) similar to a pilot project in Drake Landing, Alberta, which permits long-term storage of cold and heat in natural underground sites such as aquifers, bedrock and caverns. In addition, coupling concentrated solar power (CSP) plants to experimental phase-change materials that also can store energy for extended periods, pumped-storage hydro (PSH) and conventional hydroelectricity, widespread adoption of hydrogen as a fuel, and ‘demand response’, or paying people to reduce energy use when supply is tight would be required.
Jacobson’s critics say that he assumes energy storage capacity more than double the entire current capacity of all US power plants. They add that there are no electricity storage systems currently available that can dependably store vast quantities of energy for multiple weeks at a time, that phase-change materials are effectively at the R&D stage, and that UTES systems on the scale required would mean deployment in nearly every community. Meanwhile hydrogen production would have to be scaled up some 100,000 times, consuming at peak rates twice the current electricity capacity of the US. Almost two thirds of all industrial energy demand would also have to be flexible to reschedule production at eight hours’ notice, which is infeasible for many operations.
Last year, the Stanford researcher used similar methodology to produce a series of roadmaps for 139 countries, including Canada, an analysis that was formally released this June. His team says that the country could be 58 percent wind-powered by 2050, with 22 percent solar, 16 percent hydro and two percent each for wave and geothermal, and that we could get 80 percent of the way there as early as 2030.
This contradicts various ‘deep decarbonisation’ energy mixes modelled in the federal government’s Mid-Century Strategy. To achieve just an 80 percent decarbonisation target by 2050, these mixes all assume large roles for hydro, nuclear and wind, with trace amounts of solar. As a number of jurisdictions and campaign groups in Canada draw on Jacobson’s analysis to make the argument that 100 percent renewables is possible, further assessment of his team’s Canadian roadmap is necessary to see if it contains similar problems as his US paper.
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