Credit: City of Sydney, 2009
What is a cool road? A road that's not hot. Its a road that can reduce your electricity bills, ameliorate climate change, & reduce mortality rates in heat waves.
In the thermal image above (Chippendale, a suburb of Sydney, NSW, Australia), the hottest bits are in orange-red, coolest bits in blue, & intermediate temperatures in yellow.
Hottest bits? Roads.
Why are they hot? Because they are black, & heated by sunlight.
And there are a lot of them. Twenty four percent of the land area of Chippendale is covered with black roads. Some other Sydney suburbs run to 36%.
On average, Chippendale is 6 Celsius degrees hotter than it would otherwise be, but for its black roads.
Problems:
● air conditioning use is increased with obvious climate change & cost impacts
● mortality rates, particularly among the young & the old, rise during heat waves
Something similar is happening in your town or city.
Simple solution: pale roads. This means concrete.
Concrete roads are more expensive, but last longer & have lower maintenance costs.
A New York study found that an investment of $58 million in cool roads in that city would reduce annual electricity bills by $57 million. I.e. one year payback, ignoring other benefits.
In Australia, a study indicated that by replacing black roads with cool roads, as they come due for replacement, cities could be cooled by 1 or 2 Celsius degrees by 2020. This is equivalent to taking a high cost, peak load power station off line in each state.
A trial is to begin in chippendale next month.
Other measures include:
● grow trees to shade suburban streets
● pale roofs
● pale parking lots & driveways
Pocast can be found here:
http://www.abc.net.au/radionational/programs/breakfast/first-trial-of-cool-roads-to-combat-warming/5485844
More about sustainability in Chippendale:
http://sustainablechippendale.com/ / cool roads combat climate change Australian sustainability expert light coloured colored colour color pale heat reflective roads pale roofs more trees reduce temperatures big cities six degrees improbable first trial cool road pale more reflective media black tar laid down Sydney concrete cement /
