Sitka Longliner Goes Hybrid-Electric

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Category: Local News

Created on Friday, 03 January 2020 00:43

By GARLAND KENNEDY
Sentinel Staff Writer
    The F/V Sunbeam is close to becoming Sitka’s first plug-in hybrid diesel-electric fishing boat.
    “It will probably save me maybe 30 to 40 percent on fuel,” Fabian Grutter said in an interview on the boat, “but another big savings is my main (diesel) engine won’t run 40 percent of the time, probably.”
    Grutter has longlined and gillnetted in the Sitka area with the Sunbeam for more than two decades. He grew up in Southeast and learned to fish when he was young, though both of his parents emigrated from Europe.
    Grutter said his interest in electric propulsion systems began several years ago, when he converted his truck to all-electric operation.
    The finishing touches of the plug-in hybrid conversion involve programming the controller, which drives and regulates the motor, he said. Grutter is unsure when the first sea trial will be.
    At its berth in Crescent Harbor, the Sunbeam looks like an ordinary longliner, but inside, the engine compartment is open and exposed. Lengths of wiring, a row of batteries, and a sleek electric motor on a custom welded aluminum bracket surround the decades-old diesel engine.
    Grutter cites a number of reasons, besides the savings in fuel costs, for his hybrid project on the Sunbeam: “A combination of performance and cleaning up the environment, and just quietness. All day long gillnetting you’re running your diesel 18 hours and you’re not even going anywhere. You’re moving 2,000 moving parts for 18 hours straight.”
    A reduction of noise levels while gillnetting was a key motive for the project, he said.
    “Every time I’m gillnetting or longlining there will be silence,” Grutter said. “The goal is to only use the diesel to run around.”

Favian Grutter looks out from the head of his boat, the F/V Sunbeam, where he has installed wiring for a new electric motor. The shaft of the small motor can be seen sticking out from a metal plate just above his main diesel engine. (Sentinel Photo by James Poulson)

    He said Sunbeam’s diesel engine can charge the 70 kilowatt battery bank with an alternator.
    “Basically, it could charge that whole big battery bank in four or five hours cruising, then you shut the diesel off. And the theory is that it should get me gillnetting all day long, basically 12 hours of putzing around the net on one charge.”
    The batteries in question are lithium iron phosphates, a non-flammable form of lithium ion batteries. The boat is a plug-in hybrid because the batteries can also plug into dock power to charge.
    Grutter said he learned how to do the conversion online. “Hopefully, I’ve done all the wiring right,” he said as he pointed to a wiring diagram which resembled a plate of spaghetti.
    “They built a boat in Norway that’s made out of carbon fiber, the same size as this boat,” Grutter said. “It’s a commercial boat called F/V Karilene. And it’s got the best combination, it doesn’t have a main (diesel engine), it just has a genset (generator), a battery, and a motor. Obviously it has a bigger battery than this (on the Sunbeam), but it can go offshore and fish all day, come back without starting the generator.”
    Explaining the gains in the energy efficiency he expects, Grutter said only about one-fifth of the energy from diesel fuel ends up propelling the boat. The rest, he said, is lost to heat and noise. In contrast, he said that the electric motor would allow about 90 percent of the energy to go into propulsion.
    Pointing to the massive diesel engine, he said “weight-wise, horsepower wise, you could do the same thing with a 200-pound (electric) motor, where this diesel is 1,800 pounds. Especially if you have cooling, my motor doesn’t have cooling. That’s like a magic point... that means that you can have a motor that’s 100 pounds that can do 250 horsepower – it’s incredible.”
    But there’s another motive behind the diesel-electric conversion: engine maintenance. “The electric motor is rated 50,000 hours (before maintenance) and then you can take them apart, there’s a bearing on one side, and a seal, and that’s it, and you can put it back to together,” Grutter said. “The diesel, they’re good for 20,000 hours and then you’ve got to pull them out and it’s 20 grand to rebuild them.”
    Grutter showed his confidence in the long-term efficiencies of electric propulsion with the $20,000 investment in his specialized batteries. But that’s just under $300 per kilowatt, he said, which made it a bargain.
    “The biggest point,” he said, “is that the batteries have finally gotten cheap enough that it’s worth doing now, and it hasn’t been before.”