PUBLISHED IN the climate examiner, 21 march 2016
Hydroelectricity has long been assumed to be the cornerstone of any future low-carbon economy. It is the single largest source of renewable energy in the world, representing 16 percent of global electricity generation—a figure that is set to grow by about three percent a year over the next quarter century. Here in Canada, hydro delivers 60 percent of our electricity, a figure that climbs to 90 percent in British Columbia and 96 in Quebec.
It’s cheap. It’s clean—emitting just six grams of carbon dioxide CO2 per kilowatt hour generated compared to the 1024 grams emitted by coal, the 45 grams emitted by photovoltaic solar and the 16 grams emitted by wind. And, crucially, it is not intermittent like other renewable energy sources such as wind and solar. That is to say, while the sun does not always shine and the wind does not always blow, hydro is ‘always on’, allowing everything in a modern economy from hospitals to factories to keep running without fear of regular black-outs.
It’s also flexible, offering the ability to quickly ramp up or wind down the amount of electricity dispatched depending on need. As a result of all these favourable attributes, in most scenarios for the transition to a clean-energy economy that we need in order to prevent catastrophic climate change, hydroelectric does a lot of the heavy lifting. When Ontario switched off its coal plants, it was hydroelectric, together with nuclear, that filled the gap.
But what if climate change itself started to make hydroelectricity less dependable?
This appears to be the worrying conclusion of some PICS supported researchers who have looked at projections for the rest of the century for British Columbia, but which have worldwide implications.
The story begins at the top of the province’s mountain ranges. As is happening around the globe as temperatures increase, glaciers here are melting rapidly. A bit of annual melt isn’t a problem; indeed, billions of people depend upon this meltwater. But the snow that falls upon the glaciers each year is supposed to make up for the losses, and that’s not happening any more.
Historically, researchers have kept what amounts to a sort of ledger that tracks this process, accounting for the water accumulating as ice and the water exiting as runoff. This has been useful enough in the past when glaciers changed shape slowly and their motion could be measured directly. But projections of future glacier change need more than this ledger system. They also need to account for the underlying physics of glaciers—how ice moves—and earlier studies came in for criticism for their failure to do so.