Leading the way to hybrid diesel electric propulsion

Originally Published September 12, 2024 via National Fisherman

In 2021, the Alaska Longline Fishermen’s Association (ALFA) initially received funding from the Energy Transitions Initiative Partnerships Project for modeling and analysis of alternative propulsion systems. Based on that work, the original plan—developed in conjunction with the National Research Energy Laboratory—was to put a Transfluid clutch, electric motor, and batteries on Eric Jordan’s troller, the I Gotta, but Jordan has withdrawn his vessel from the project for personal reasons but continues to lend financial support. After receiving $700,000 in additional funding from the Department of Energy’s Vehicle Technology Office and $500,000 from the Department of Energy, the new plan is to outfit Jeff Turner’s troller longliner, the Mirage.

“The Mirage is a troller/longliner freezer boat,” says Chandler Kemp, owner of Kempy Energetics in Dillingham, Alaska, and Energy Efficiency Consultant for the project. “The Mirage has a genset on board, which allows the vessel to keep its batteries charged on longer trips without starting the main engine,” says Kemp. He notes that Jordan’s boat, being a day boat, would have been able to recharge its batteries every night using Sitka’s abundant hydropower, the Mirage stays out for a week at a time and will be less efficient because of the conversion loss involved in charging from a genset. “The percent fuel savings will be lower for an operating profile like the Mirage than for the I Gotta,” says Kemp, but he roughly estimates a 20 percent fuel savings and reduced wear and tear on the main engine. “This can lay the groundwork for decarbonization and show the benefits of the system.”

Jeff Turner’s Mirage has a 300-hp Cummins 6C and a Bollard 32 kW genset. Because the Transfluid gear and motors are sandwiched between the engine and reduction, the vessel’s powertrain has required some changes in the Transfluid system being ordered. “There’s a new reduction gear,” says Kemp. “It had a Twin Disc 3.83:1, but that wasn’t going to work, so now it will have a Revermatic at 3.5:1.” Kemp notes that the project is back on track, with the Mirage expected to be ready to go in the spring of 2025.

Hybrid power has the potential to bring considerable savings and other benefits to the fishing industry, and the U.S. and Canadian governments are subsidizing a few conversion projects. The efficiency of electric power is shown first in deck equipment. With support from Acme Seafood Company and AgWest Farm Credit Services, ALFA has already installed electric deck equipment on one of its member vessels. However, as far as propulsion is concerned, Kemp acknowledges that the technology remains years away from being widely adopted. “I think the price will decrease, and they will be made more affordable. In fisheries with operating profiles where they can charge on shore, and maybe have a genset as a range extender, that’s where these systems could be profitable first.”

- " style="box-sizing: border-box; -webkit-font-smoothing: antialiased; border: none; font: inherit; margin: 0px; padding: 0px; display: block; width: 300px; height: 250px; background: transparent; overflow: hidden; vertical-align: middle; max-width: 100%; max-height: 250px;">

Kemp wonders what may come before, which is a combination of alternative fuels and electric motors. “What I think could happen—depending on the price of diesel and what happens in other sectors—is that we could see hydrogen fuel cells being used for propulsion and a battery incorporated into that system to augment the fuel cell,” he says. "But as I said, the vessel's operating profile will determine what makes the most sense."

As the push continues to decarbonize the world's fishing fleets, ALFA, with help from Kemp, is among the organizations leading the charge in exploring options.