Is a 100 per cent clean-energy city possible?

Photo credit: quiquefepe. Source: flickr.com

As urban centres go, Vancouver is an eco-warrior’s haven. But in terms of hard numbers, according to a new report out of Simon Fraser University, the city doesn’t quite live up to its reputation: it gets only 30 per cent of its energy from renewable sources.

That report suggests a two-pronged strategy to tackle the city’s 100 per cent-renewable goal, set for 2050. First, get rid of natural gas. Second, cut transportation emissions by making the city denser.

Buildings are Vancouver’s biggest greenhouse gas emitter, belching out 56 per cent of the city’s total carbon in 2014. And heating and cooling technology is largely to blame.

Combustion furnaces, says the SFU report, make up over 70 per cent of Vancouver’s market share for space heating technology. One policy projection aims to lower natural gas use by switching to other heating strategies. Those include passive heating designs, wherein the house maintains a relatively static temperature – what a 2016 Vancouver city council report called a “key tool” in reaching the city’s target.

The twinned approach, according to the report, would also see a city designed to lower the “intangible cost” of walking and taking public transit.  Generally that would mean more people in less space, making high-rise condos an essential instrument to emissions reduction. Except the city, in its 2016 report, acknowledges these condos often represent some of the least energy-efficient designs, with natural gas heating systems and poor insulation directly resulting from the use of specific materials—such as glass and exposed concrete—that are so prevalent in today's high-rises.

But there’s hope. Energy consumption for density-friendly high-rises could be slashed by half with upgrades to ventilation and enclosure materials. Even something as simple as replacing dirty air filters may increase airflow and reduce the need for gas-powered furnaces and air conditioners.

Replacing building materials such as concrete with wood, as UBC did with its Brock Commons design, can reduce emissions substantially. The 17-storey high-rise is expected to save 500 tonnes of CO2 compared to concrete-framed structures. And strategic use of window glazing, blinds, and awnings could keep heat out in the summertime, according to the 2014 Greenest City Action Plan report.

Retrofitting old high-rise buildings and designing new ones in the spirit of passive heating—and making sure those dense urban spaces are properly served by walkable amenities and efficient transportation—could be enough for Vancouver to reach its renewable goal after all. 

By Malone Mullin, 29 June 2017

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This article was written for Clean Capital News a free bi-weekly publication dedicated to producing topical articles on sustainability and clean technology that advance our understanding of issues like climate change and help generate solutions for a more sustainable future.

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