Smart Surfaces Pave the Way for Healthy, Wealthy Cities

Study shows sustainable surfaces in cities may save money and environment and create jobs.

In June, a group of the world’s climate change leaders warned that Earth could face irreversible temperature increases if greenhouse gas emissions aren’t reduced by 2020. While the group, dubbed Mission 2020, urges energy policymakers to move the world to 30 percent renewable energy in the next three years, it noted that much of the needed change will fall to cities and municipal governments.

The dire warning is alarming, but what if one of the simplest, and most natural, elements could be the solution? What if better harnessing fundamental properties of life on Earth—sun and water—could not only reduce rising climate temperatures, create jobs and improve quality of life, but also secure billions of dollars for cities in net financial benefits and potentially half a trillion dollars nationally?

A recent study by the U.S. Green Building Council (USGBC) is one of the first to research the costs and benefits of smart surface technologies, including cool roofs, green roofs, solar polar, urban trees and reflective pavement. The study focused on El Paso, Texas, Philadelphia and Washington, D.C. The results: Across the board, using smart technologies citywide, and especially in low-income neighborhoods, produced financial benefits that exceeded costs.

The results for Philadelphia indicate a possible net present value of $3.57 billion. (Image courtesy of USGBC.)

The results for Philadelphia indicate a possible net present value of $3.57 billion. (Image courtesy of USGBC.)

How can these smart surfaces make such an impact, and what are these “smart” surfaces?

Cool roofs are designed to reflect more sunlight and absorb less heat than a standard roof. They are made with a highly reflective type of paint, sheet covering or highly reflective tiles or shingles. These roofs enhance ambient cooling, reduce energy bills, improve air quality, reduce local air temperatures—referred to as the urban heat island effect—and lower peak electricity demand.

Green roofs are rooftops layered with a waterproofing membrane, soil and vegetation. Benefits include reduced cooling and heating energy use, reduced greenhouse gas emissions, improved air quality and reduced stormwater runoff. They also enhance a building’s amenity and aesthetic value.

The U.S. Coast Guard headquarters in Washington, D.C., has a thriving green roof. (Image courtesy of U.S. General Services Administration.)

The U.S. Coast Guard headquarters in Washington, D.C., has a thriving green roof. (Image courtesy of U.S. General Services Administration.)

Solar photovoltaic panels have been used for decades, but there has been an increase in their use on larger scales thanks to advances in the technology. The panels are an assembly of solar cells that convert sunlight into electricity. Combined with an inverter and other hardware, they provide electricity to a grid or homes and buildings on which they are installed. Solar panels can help reduce greenhouse emissions and fossil fuel consumption.

Reflective pavement and urban trees are two solutions to battle the negative effects of pavement, which covers nearly 30 to 45 percent of cities. Conventional paving materials can heat up to 120°F to 150°F and warm the air and stormwater runoff. Cool pavements can be created with existing paving technologies to be more porous, and coatings for reflective surfaces—or even grass paving—can help create ambient cooling, reduce energy use and greenhouse gas emissions and improve air quality. In addition, planting more trees is a simple solution to air quality and helps with cooling and drainage issues.

This study serves as start for cities as they move toward finding a complementary balance of modern life and environmental sustenance. While no solutions are immediate, the long-term benefits of incorporating technology to better use the natural world around us seems to be worth any upfront costs.