Travis Wallace’s hometown of Crawford, Maine, doesn’t sit directly on the coast, but the Washington County community has its share of lobstermen and others who work in industries that rely on the water and use heavy machinery to navigate the Gulf of Maine.
So when Wallace first heard about the potential of thermoelectric power generation — which relates to the production of electric power from waste heat — the then-Maine Maritime Academy undergraduate could easily picture the technology’s possibilities for the maritime industry. A marine vessel running on the energy created by its own exhaust heat? The potential for millions of dollars in energy savings? How could Wallace not be interested?
Now a graduate student at UMaine, Wallace is combining his pursuit of a master’s degree in mechanical engineering with running his own start-up business centered on the thermoelectric technology.
While at Maine Maritime, Wallace worked with other undergraduate students and faculty to build what is believed to be one of the first thermoelectric-powered hybrid marine vessels in the world. He founded his company, Thermoelectric Power Systems LLC, with the goal of developing and marketing the technology to the marine industry.
“We took an encapsulated life boat and retrofitted it with a new diesel electric propulsion system so we could utilize the energy harvested from the generator and put it back into the system,” says Wallace, who is an advisee of UMaine assistant Professor Zhihe Jin and Paul Wlodkowski, a Maine Maritime engineering professor who holds a graduate faculty appointment at UMaine to work on a STEM project. “Basically what it’s doing is reducing the load on the generator and therefore reducing the fuel consumption.”
UMaine electrical and computer engineering associate professor Bruce Segee is involved in the instrumentation and automation of the project. Maine Maritime’s Peter Sarnacki, an associate professor of engineering at Maine Maritime with technical experience in the type of propulsion system with which Wallace is working, is also involved in the research.
Wallace has set an aggressive goal of working toward a 5 percent decrease in fuel consumption for the entire fleet in Maine, from lobster boats to luxury yachts. That 5 percent reduction translates into millions of dollars per year.
So far, Thermoelectric Power Systems, or TPS, has already garnered more than $175,000 in grants for research and development from organizations such as the American Bureau of Shipping and the Office of Naval Research. TPS learned this winter it had received a small but prestigious grant from the Portland, Maine-based Libra Foundation. The grant was enough to update the thermoelectric generator’s data acquisition systems, in order to keep the technology up to industry standards.
Wallace has worked with UMaine’s Foster Center for Student Innovation to apply for grants and get out the word about TPS.
“The staff was very excited and very instrumental in helping me get my proposals together,” says Wallace, who has office space at the Foster Center. “My first proposal was extremely technical, because it was a different style of writing than I was used to. It would have put you to sleep, basically. So we sat down and went through quite a few drafts to try to make it more marketable.”
The numbers in terms of potential energy and cost savings should be attractive to the industry. According to a study by MAN B&W Diesel Group, a premiere diesel engine manufacturer, approximately 30 percent of the energy contained in fuels is lost through heat that escapes up the exhaust stack. TPS’ own numbers show a return on investment of three years can be expected – assuming an annual fuel savings of $2,000 – for an average commercial fishing vessel.
Wallace’s retrofitted vessel is unusual-looking – it looks more like a submarine than a boat – but has worked so far in testing. The technology involves installing a thermoelectric generator (TEG) in the exhaust path of a vessel’s internal combustion system, thus enabling the recovery of energy that is otherwise lost through heat in the exhaust gases. The TEG is able to convert a thermal gradient into electricity thanks to a phenomenon known as the Seebeck Effect. Thermoelectric material embedded in plates in the generator convert the heat to electricity. The TPS generators are also able to recover heat lost not only through exhaust, but also from peripheral systems such as engine jacket water or engine lubricant oil coolers.
The TPS technology is designed to be similar to existing technology used extensively throughout on-board vessel systems in order to facilitate easier conversion to the TPS generators.
Thermoelectric generators are also used in the automotive industry, but there had been little thought to their use in the maritime industry. Wallace served as a team leader on the project while at Maine Maritime. Two years ago, the team placed its TEG on the Research Vessel Friendship for testing in the dock and waters of Castine Harbor.
“The testing sessions were kind of one of the defining moments, because we put so many hours into the vessel and to hear it come to life was something special,” Wallace says. “After we got the thermoelectric working and flowing into the system, that was something special too, because it kind of validated our claims that we could do it.”
For his master’s thesis, Wallace has been creating a high-power working prototype of the thermoelectric generator.
“The [prototype] we have is a very small wattage, low power (180 watts) and the generator set is 27 kilowatts,” he says. “We realized the 180 watts isn’t going to make a big dent in the 27 kilowatts, and that’s why my thesis is trying to make a high-power density thermoelectric generator. I’m working on increasing the power output of one of the heat exchangers. If we can go from 180 watts to something more substantial, maybe 1 kilowatt or five kilowatts, that’s going to make a difference.”
Following his graduation later this year, Wallace intends to market the technology by first approaching segments of the marine industry that rely on small-scale boats – the lobster fishing industry is one that he intends to target – and then work his way up to larger vessels.
He is grateful he had the opportunity to work on thermoelectrics while at UMaine, even though none of the College of Engineering faculty is specializing in that area.
“UMaine has a great engineering program, and they let me work on what I wanted to do, so it was a good fit,” he says. “They were going to let me work on what I wanted to do, so it was a good fit. I’ve had great support for this through my advisors and the innovation center.”
Image Description: Travis Wallace