Waste Heat Is Free Energy. So Why Aren't We Using It?
Waste Heat Wikimedia Commons, Jorge Royan In the next few years, the stale, thick heat produced by the London underground will no longer drift uselessly into the atmosphere. Instead, some of it will warm 1,400 nearby homes, cutting heating bills by about 10 percent. Recycling heat is quite common in Europe. Denmark gets roughly half of its electricity from recycled heat, followed by Finland at 39 percent, and Russia at 31 percent. In the U.S., it’s just 12 percent. According to a report by Lawrence Livermore National Laboratory and the Department of Energy, the U.S. wastes more than half of the total energy we produce—mostly as heat, but also as gas, biomass, and methane. Using that waste could reduce carbon dioxide emissions by 17 percent. “It’s free energy, essentially,” says Brendan Owens, vice president of LEED at the U.S....