A year after pavements in a treeless north Los Angeles neighbourhood were coated with solar-reflective paint, air temperatures are up to 1.9°C lower, making the area’s increasingly hot summers a touch more bearable.
Last July, the city of Pacoima partnered with roofing manufacturer GAF to apply a cooling pavement coating over 65,000 square metres of hard surfaces—streets, a playground, a basketball court, and two parking lots, all within a 10-block perimeter, reports Smart Cities Dive.
GAF’s first eight months of data show ambient air temperatures two metres above the ground that were on average 1.5°F (0.8°C) lower on sunny daysand up to 3.5°F (1.9°C) cooler during an extreme heat day, compared to a neighbouring community without cool pavement.
The two-metre mark was critical because that’s roughly how tall people are, said Jeff Terry, GAF’s vice president of corporate social responsibility and sustainability.
The pavement itself averaged 10°F (5.5°C) cooler on sunny days, with no negative impacts observed.
“We’re very excited about the interim findings,” Terrysaid, adding that people in Pacoima and the neighbouring reference community would like to see more public surfaces coated.
Cool pavement technologies are also being explored in other parts of Los Angeles, and Phoenix, Arizona finished applying a reflective coating on 160 kilometres of its streets in June.
While it can be hard to “tell the difference between 110°F and 100°F,” a largely treeless community like Pacoima, and many others like it, must seize every opportunity to cool streets down, said LA city council member Monica Rodriguez, who represents the community.
The GAF team is now rolling out the second phase of the project focused on cool roof technologies, and a 100-square-block area with reflective paint could be a next step. A final research report is expected in early 2024.
Meanwhile, “the counties of Los Angeles, Ventura, and San Diego in California have 4,800 acres of suitable solar project space alongside highways and rights-of-way,” PV Magazine writes. Those expanses could “host over 960 megawatts of solar capacity, generating 1,960 gigawatt-hours per year,” enough energy to power 270,000 homes, according to a recent report by Environment America.
The study is good news for California, which will need “to triple its solar capacity to meet its 100% clean energy requirement,” the magazine adds.
Right-of-way solar has a small but proven track record across the United States, with two successful projects outside Portland, Oregon, one along a Georgia highway, and three projects in Maine with a combined capacity of 8.5 megawatts.
“Expected to save the state US$7.2 million over the next 20 years on electricity costs,” the Maine arrays have an added boon: courtesy of the state transportation department, the ground beneath and around the solar arrays has been seeded with pollinator-friendly plants.
