The skyscrapers of the future could be built with the garbage of today
Green buildings made of recycled materials are the hot new thing.
The home of the future won’t look like The Jetsons. It won’t come equipped with a flying car or a robot maid. While it will deploy a slate of clean-energy technologies that the cartoon’s creators couldn’t have imagined — solar windows, lithium-air batteries, artificial intelligence— it will be made largely from wood and used materials, like recycled cement and carpet.
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.”
“For building products, there’s been a growing interest — still fairly new — in the environmental impacts of the products,” Beardsley said. “How long does it last? Is it a durable product, or is it going to be replaced soon and go into a landfill or incinerator?” She added, “Now there are new products that will bind carbon and become a carbon sink.”
Producers are looking to construct large buildings, even skyscrapers, out of wood. Trees soak up carbon from the atmosphere and store it in their leaves and branches. A wooden building locks away the carbon indefinitely. So long as forests are replenished, and producers don’t burn too much coal, oil or natural gas in the shipping and manufacture of wood parts, it’s a win for the climate.
“We know we’re getting denser, and we don’t want to increase sprawl by having only low buildings,” Beardsley said. “There has been investment and research for a couple of decades now to develop timber wood products that are much stronger and can support skyscrapers.” By one estimate, a 20-story wood building would sequester some 3,000 tons of carbon — the yearly output of around 600 cars.
Even in wood buildings, designers use concrete for the foundation and steel for fittings to connect timber beams. Some scientists and engineers are working to shrink the carbon footprint of these essential materials. “All of the recycling efforts to date have created the opportunity for new ideas and new products,” Beardsley said.
Steel manufacturers, for example, are forging new parts from scrap metal. In Sweden, scientists are using algae to soak up carbon emissions from cement production. Across the pond, Solidia Technologies, a US concrete producer, has developed a new kind of concrete that absorbs carbon dioxide when it sets.
Producers are also looking to use other materials from recycled goods, fashioning insulation from recycled cardboard and carpet from old plastic bottles. “Now, much of the carpet that is available is all recycled content and can be recycled itself again,” Beardsley said. “It’s really a circular process where there is no waste.”
It may be that the homes of the future will be made from today’s trash — unwanted wood, metal, cardboard and plastic, along with planet-warming carbon pollution that can be plucked from the sky. Add in smart lighting and high-efficiency appliances, and you can make a building with a minimal carbon footprint.
“If you have the opportunity to [use] solar or wind, you can create a net-zero home, and that’s even better,” Beardsley said. “We have solutions, and we’re implementing them.”
Nexus Media is a syndicated newswire covering climate, energy, politics, art and culture. Owen Agnew, Jeremy Deaton, and Josh Landis contributed to this report.