Experts say these technologies will put a big dent in our carbon output. And they are getting cheaper every day. “We can build net-zero buildings,” said Elizabeth Beardsley, senior policy counsel at the U.S. Green Building Council, which certifies energy efficient buildings. Beardsley is in Bonn, Germany this week for the 2017 UN Climate Change Conference, pressing the case to make all buildings produce at least as much energy as they use by 2050. “We’ve been working on climate for decades,” she said. “We feel strongly that it’s time to act on climate.”
Buildings generate pollution in two significant ways. One is from power use. Residential and commercial buildings account for 70 percent of power consumed in the United States — electricity that largely comes from burning carbon-intensive coal and natural gas. The second way buildings generate pollution is in the use of materials like steel and concrete, which have a sizable carbon footprint.
To cut power use, Beardsley said that homeowners and building managers can install LED lights, generate electricity from rooftop solar panels and use smart water heaters and air conditioners to store that clean energy. She described other technologies, like windows that automatically tint when rooms get too warm, saving energy on air conditioning while keeping homes comfortable.
“Lighting manufacturers have developed systems that use sensors to know when you’re there and when you’re active,” Beardsley said. “These are also getting cheaper and cheaper.”
That’s only part of the problem. Beardsley said that firms must also tackle the more difficult task of constructing buildings from low-carbon materials, instead of steel and concrete. Manufacturers make steel by heating iron ore and coal in a blast furnace. They make cement, the binding agent in concrete, by heating limestone and clay in a kiln. Heating coal and limestone also releases carbon dioxide.
It takes a tremendous amount of energy to generate the heat needed to make steel and cement, and producers generate that heat by burning coal or, less often, natural gas. Together, the production of steel, concrete and related building materials generates more carbon pollution than every car, truck and minivan on the planet. Energy geeks refer to pollution associated with buildings materials as “embodied carbon.”
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