This year, Toronto has become the hub for green roofs! Torontist took a look into what made this happen and why green roofs are perfect for cities.
There are approximately 500 green roofs, big and small, in Toronto. This is thanks to a 2010 bylaw [PDF] requiring all new developers to cover between 20 and 60 per cent of their buildings with vegetation. It’s the first (and, for now, only) regulation of its kind in North America, making Toronto uniquely positioned for environmental design.
The bylaw is why the 41-story RBC WaterPark Place [PDF] at Bay Street and Queens Quay has three green roofs that together could fill a NFL football field.
Developers can opt out of installing anything remotely grassy for a fee. But Jane Welsh, City Hall’s project manager for environmental planning, told Torontoist only five per cent of buildings choose to go sans-green roof.
Welsh also says municipally-owned buildings install a green roof anytime there’s a repair or replacement to the top of the building, when feasible.
During summer heat air conditioners are used extensively and this can increased energy consumption can be crippling. Black outs occur in the summer thanks to people cooling their homes and workplaces – but these power issues can be avoided. By simply painting roofs white it can help cool buildings and lower energy bills. Painting multiple roofs white can a really positive effect on a large area.
They found that urban expansion alone could increase summer temperatures by up to 6°F in some areas in addition to greenhouse gas-induced warming by 2100. The Mid-Atlantic and Midwest seeing the biggest overall summer temperature increases.
In all areas, white roofs could completely offset the combined increase in temperatures, and if deployed across the entire megapolitan area, could actually reduce summer temperatures compared to the 1990-2010 average.
The benefits of cool roofs were particularly prominent for the urban areas stretching from Washington, D.C. to New York, Chicago and Detroit, and California’s Central Valley.
Cooler summertime temperatures could reduce demand for air conditioning, which could both save money and reduce the chances of electricity grid blackouts.
In one year California was able to increase power output from solar panels installed on roofs from 1,000 MW to over 2,000 MW. This is impressive and hopefully this trend continues in the very sunny and warm state!
To put this in perspective, it took California over 30 years to build 1,000 MW of rooftop solar, hitting that landmark in early 2013. Today, California is closing out the year with more than 2,000 MW of rooftop solar systems installed statewide. The California Public Utilities Commission’s (CPUC) latest figures report 1,917 MW of rooftop solar, but those numbers exclude basically all of Pacific Gas and Electric’s 2013 installations, by far the largest market in the state, as well as a significant number of installations in other utility territories.
Energy is still delivered via large power stations which can fail and leave entire regions without electricity. The future requires a more distributed energy grid that is a combination of large and small electricity generators, doing so will ensure electricity is not so heavily impacted by a rise in the cost of single fuel source.
Light provides us with infinitely free energy, all we need is a way to capture it and year-over-year it’s getting easier to do so. Combing solar power and a distributed power grid opens up new opportunities and an enterprising company from always cloudy Vancouver have stepped up.
Gridbid will turn a homeowner’s roof into a power source and provide an ongoing revenue for the owner while making our energy source a little better.
Gridbid, allows homeowners to auction the solar installation rights to their roofs online. The company says solar installers can save as much as 80% of what they normally spend to find roof-top space, while the average residential utility bill drops between 10 and 35%.
He and his partners knew getting into solar was next. Proving the importance of engaging in customer discovery conversations, they talked to over 150 different people in the solar market to identify the key problems. The problems were roof acquisition and financing for projects. Thomas shared what’s driving him and his team, “we are going to learn faster than anyone, and ultimately build a very large solar auction and financing platform that will make going solar painless for any person, or organization who owns a roof.”
In New York City the US Postal Service will house the largest green roof in the state. Is it just me or is NYC becoming one of the greenest cities in North America?
The new 2.5 acre park sits on the seventh story of the 2.2 million square foot facility. The new roof will last 50 years, which is twice as long as the roof they just replaced. Polluted stormwater runoff will be reduced by up to 75% in the summer and 35% in the winter. The roof will also help the facility reduce its energy use by 30% by 2015. Native plants and trees are used on the roof and emphasize drought tolerant and low maintenance species, which will be watered with collected rainwater. Planted species include coral carpet, Calamagrostis grass, John Creech, Immergrunchen and Fudaglut sedums. The landscape of the roof was designed by Elizabeth Kennedy Landscape Architects.