When Thomas Edison built the world’s first commercial power plant in Manhattan in 1882, he also sold the exhaust heat from its coal-fired boilers to nearby buildings. Since then, scientists and engineers have sought new technologies that would expand on Edison’s elegant idea of using energy twice. The latest Holy Grail: perfecting thermoelectrics, materials that can convert heat into electricity.
Matt Scullin, 28, is trying to improve the technology which in its current state isn’t very efficient, costs a lot, and is difficult to manufacture on a large scale. The New York City native, who earned his PhD in materials science from the University of California at Berkeley, was part of a group of researchers at Lawrence Berkeley National Laboratory that in 2010 discovered a way to use silicon—which is cheap and easy to handle—as an efficient thermoelectric material. His two-year-old San Francisco startup, Alphabet Energy, has licensed the patent and is working to commercialize silicon-based thermoelectric generators for utilities, manufacturers, and other industries that stand to benefit from reusing heat.
Scullin, who paid his way through grad school in part by DJing at concerts and art shows and consulting for venture capitalists at $500 an hour, says silicon is an ideal material to work with because there’s already an infrastructure for it. “We’re piggybacking off of the semiconductor industry to build a scalable business,” he says. Rather than spending millions to create a factory and supply chain from scratch, Alphabet Energy initially will outsource production to semiconductor fabricators so the 12-person team can focus on product development. Using silicon “gives Alphabet Energy a good head start,” says Harry Zervos, a technology analyst at research firm IDTechEx in Cambridge, England. Alphabet landed $12 million in venture capital in September.
Alphabet’s technology is still being tested in the lab, but Scullin, who is careful not to divulge too much for “competitive reasons,” says he is planning pilot tests for next year. He says the thermoelectric device looks something like a solar panel, with the silicon material wedged between two pieces of steel. A heat source warms one of the steel pieces, creating a temperature differential that generates electrical voltage. Designed to be easily manufactured in any size, from a few inches long to as large as a flatbed truck, Scullin says the technology could be useful in industries from biomedicine to kitchen equipment.
For now, Scullin is most interested in tapping exhaust gas. Putting one of Alphabet’s thermoelectric generators in a smoke-billowing chimney could produce enough electricity to provide 10 percent to 100 percent of the facility’s power, cutting its energy bills significantly, he says. Another application: reusing vehicle exhaust to power a car’s electrical system. General Motors and other automakers are developing their own thermoelectric generators, but Zervos says they’re a long way from being integrated into vehicles.
Arun Majumdar, now director of the U.S. Energy Dept.’s Advanced Research Projects Agency-Energy, introduced Scullin to waste heat technology while serving as his PhD adviser at Berkeley in 2006. A visit over Christmas break in 2008 to the cramped boiler room of Manhattan’s swanky Helmsley Building gave Scullin a new idea for how to apply his materials science background. Aware that massive amounts of excess steam were regularly released into the sewers beneath Manhattan, he bet a thermoelectric device could fit the space and cost relatively little. He realized, however, that building managers, factory owners, and power plant operators accustomed to removing heat pollution from their facilities would adopt the technology to harness excess energy only “if we build a product that’s supremely easy to use” and “economical.”