The Lebanon, N.H.-based company SustainX, which grew out of work conducted at the Thayer School of Engineering, received its first U.S. patent last week for a new energy storage technique, according to SustainX Board Chairman and Thayer Dean emeritus Charles Hutchinson.
The patent is the first to cover claims for "isothermal compressed-air energy storage" technology a method that maintains air at a constant temperature as it is compressed and expanded, according to Hutchinson. The new technology makes it possible to store electricity without the use of batteries, he said.
"The issuance of this patent is a milestone for SustainX, because it solidifies the commercial position of our core technology isothermal gas cycling in pneumatic cylinders," SustainX President and CEO Thomas Zarrella said in a press release.
SustainX's technique uses electricity to store energy by compressing air in a tank. Electricity can then be retrieved by running the system in reverse to release the air, according to Hutchinson.
To minimize energy loss, engineers at SustainX developed a technique to transfer heat to either the surrounding atmosphere or a body of water, according to the press release. Energy can then be recovered from the air or water, or from a "source of low-grade waste heat," the press release said.
Because the system does not directly use any fuel, its use could reduce reliance on power plants that release large amounts of pollution.
"Everyone's talking about wanting to do clean tech," Hutchinson said. "Batteries are not very environmentally friendly, whereas this uses no fuel and is very environmentally friendly."
The technology is particularly suited for situations that require large amounts of energy storage with minimal waste, he said.
"There is an increasingly urgent demand for bulk energy storage in power grids, and our technology is a leading candidate for meeting that demand," Zarrella said in the press release.
Renewable energy developers can also use the compression system to store electricity produced by resources that are not constantly available, Hutchinson said.
"Because the wind never seems to blow when you need it, you can generate electricity but you don't always use it right then," he said. "Similarly, the sun doesn't always shine when you want it to."
SustainX was co-founded in 2007 by Hutchinson and Dax Kepshire Th'06, Ben Bollinger Th'04 and Troy McBride Th'01, according to the press release.
"I was teaching a seminar, and [Kepshire] brought the idea for the technology that became SustainX," Hutchinson said. "I had put together some other companies in the past, so I helped him raise some money. And all the original founders are still involved."
The company has continued to expand after receiving money from the National Science Foundation Small Business Innovation Research Program and the Energy Storage Program at the U.S. Department of Energy, among other funding sources, the release said.
SustainX is one of several startups that have grown from student ideas and collaboration between students and faculty, Hutchinson said. Institutions nationwide create a favorable environment for young entrepreneurs in various fields, he said.
Entrepreneurship at the College is vital to the Upper Valley economy, according to Catherine Carter, the president of the Upper Valley Chamber of Commerce. Student startups create jobs and attract attention to the area, she said.
"There are a lot of smart people at Dartmouth that want to do something," Hutchinson said. "It's good for the Upper Valley, it's good for the economy and it's good for the College."