It’s no secret: many places in our country are hot. While that may appeal to beach bums and bikini-lovers, it also brings with it huge environmental consequences and economic pressures, most notably in massive energy bills for cooling and a large cloud of emissions–carbon and otherwise–contaminating rainwater, which in turn becomes runoff, polluting local beaches and rivers.
But the Natural Resources Defense Council at the UCLA School of Law says that there is a solution, and all we had to do is look up. “Taking simple steps, like installing drought resistant plants on a roof surface or painting roofs to reflect the sun’s energy can dramatically reduce our dependence on fossil fuels and reduce the amount of pollution that flows to our rivers and beaches.” Considering the universal importance of drinkable water, this is a method important to the entire planet.
The process by many is being called “smart roofing,” and includes “green” roofs and “cool” roofs; many also include solar panel roofs within this category.
A new report from the NRDC lays out the benefits for its home, southern California: “if green roofs or cool roofs were installed on 50 percent of existing roof surfaces in southern California, it could save up to 1.6 million megawatt hours of electricity annually, enough to power more than 127,000 homes in California and save residents up to $211 million in energy costs each year… energy savings would cut carbon pollution by 465,000 metric tons annually.” And when these methods are described, it’s not difficult to see how simple and effective these solutions are.
The “Urban Heat Island Effect,” or the emitted high-temperatures of sun-pounded rooftops (some clocked sizzling at as high as 180 degrees Fahrenheit), creates a cumulative effect, combining to heighten the ambient temperature 13-16 degrees in metropolitan areas. A green roof is so called because ground-covering grasses and other visually appealing plants are installed, beautifying normally drab, sizzling summer rooftops and transforming them into more hospitable gardens. With cooling shade and rich plant cover, carbon dioxide and heat are aborbed, not only helping to reduce the Heat Island Effect, but also lowering air conditioning expenditure.
In fact, one square meter of rooftop verdancy can negate the particulate emissions, including carbon dioxide, equivalent to one car driving 10,000 miles. Not only that, but green roofs soak up and evaporate rainfall. According to the NRDC’s report, “installing green roofs on 50 percent of the existing roof surfaces could reduce storm water runoff by more than 36 billion gallons each year–enough to fill more than 54,000 Olympic-sized swimming pools–significantly reducing the volume of pollution reaching our local waters.”
These harken back to the simple ingenuity of ancient times and climates, where buildings in hot, sunny areas would be painted white to reflect solar radiation. The simplest and cheapest method for smart roofers, a white roof can still make up to a 60 degree Fahrenheit difference from blacktop. One square foot of white reduces carbon emissions by 1.5 pounds, essentially removing 50 cars from the road.
Last, but not least, are solar-paneled roofs, which can help provide clean, cheap energy. In a place like New York City, where roofs account for 10% of the city’s area, solar panels could produce about 16,000 megawatts of energy a year.
As time goes on, gas prices rocket, conventional energy sources become strained, and there is greater demand for alternative solutions, the question of sustainability will become a hot issue, and our roofs may be part of the answer.
If you’re so inclined, there is a lot more to learn. Ingenuity and proactive problem solving are taking place all around the world. See how and why the Museum of London’s last refurbishment included a green roof.
Another great example is the UK’s largest land owner making the roof of his stone factory entirely out of solar panels, generating energy enough to power 45 homes and hopefully becoming a beacon of an industrial embrace of alternative energy.
And there’s a different kind of energy to be gained from green roofs, as Forbes predicts: by 2018 “one-fifth of urban food will be grown on rooftops and in former parking lots.”
Back on this side of the pond, a theory behind alternative methods is posited, and it’s positive: the world could powered by sustainable, alternative energy within 20 to 40 years.
If you need more evidence that roofs are covering the needs of our future, here is Google and SolarCity $280 million investment deal, the largest such deal for home-based solar power systems in the United States.
By Thad Logan