From a distance, what appears to be an old pontoon boat with a shade canopy was tugging at its mooring near an island in Casco Bay. Up close, the retrofitted pontoon is actually something quite new: An oyster-processing barge that operates without a gasoline-fueled generator.
The shade canopy is really a 2.4-kilowatt solar panel array. What looks like a big cooler is a box of marine-grade lithium batteries tied to an inverter. They turn solar electricity into AC current to run a tumbler, water pump and other equipment. At the stern is a 20-horsepower equivalent Torqeedo electric outboard, for piloting the barge around the floating oyster cages.
The barge was built by New Gloucester-based Shred Electric. Shred has also fabricated a custom, 26-foot aluminum work boat powered by a large electric outboard. It can transport oysters and keep them cool in a solar and battery charged refrigeration unit called a ShredCube, which fits in the bed of an electric pick-up truck.
Taken together, these are the major pieces needed to operate a carbon-neutral shellfish farm from cage to plate, delivering the product to restaurants or seafood dealers without using fossil fuels.
Shellfish farming is a small but fast-growing segment of Maine’s seafood sector. Now these enterprises — and more broadly the aquaculture industry — are emerging as first movers in the quest to electrify Maine’s working waterfront.
Phasing out gasoline and diesel fuel has obvious climate and pollution benefits, but there’s also a business case for electrification. Enduring the constant drone of gas-fired generators and breathing the fumes are hazards for sea farm workers. Generators also are finicky to maintain around salt water and the noise can annoy shoreside residents. Solar and battery power could lower operating costs and create quieter coves.
Up and down the Maine coast, a transition is underway in how energy is used in aquaculture. But as with many tech transitions, this one has relied on a mix of public and private subsidies to the lower capital costs.
Key contributions have come from the federal government. Now, with funding for clean energy being pulled back under the Trump administration and Congress debating what programs to eliminate in the controversial budget bill, it’s unclear if the pace of change may slow.
Good stewards, but gasoline dependent
Shellfish farming in Maine — chiefly oysters, mussels and scallops — generates $85 to $110 million in annual sales, according to the Maine Aquaculture Association. That’s only a seventh as much as the state’s iconic lobster industry. But with 200 farms and more than 700 year-round employees, shellfish is becoming a fixture of the working waterfront.
Anyone who spends time on the water, especially in Casco Bay and the Midcoast, can spot the grids of floating cages tucked into coves and estuaries, as well as work boats shuttling back and forth.
Shellfish farmers consider themselves stewards of the environment, even though their operations depend on gasoline and diesel. But the predictable hours of operations and proximity to shore also make shellfish farms good candidates for electrification.
To envision what’s possible, Nick Planson, Shred Electric’s founder, and Chad Strater, who heads The Boat Yard LLC in Yarmouth, a marine solutions company, offered a tour in May to show off the pieces of a petroleum-free operation.
“We’re right on the cusp of doing it all,” Strater said. “The technology is there. We want this to be something that everyday (farmers) see the sense of.”
Planson and Strater operate out of the Sea Meadow Marine waterfront business hub on the Cousins River in Yarmouth. Hanging on a pier is a Level 2 EV charger. Planson plugged in his 2022 Ford Lightning.
“If we’re electrifying everything,” he said, “I can’t be pulling up in a diesel truck.”
In the pickup truck bed is the cooling unit, the ShredCube. It’s more than 5 feet long and 3 feet tall and wide. It can eliminate the need for ice or idling refrigeration trucks. The $8,000, patent-pending cooler is cloud-connected, so temperature, location and other data can be monitored on a smartphone.
The boat was built with a $181,500 federal grant for designing an electric work boat for the aquaculture industry. It’s powered by a 100-horsepower equivalent Flux Marine electric outboard, manufactured in Rhode Island. Roughly 800 pounds of batteries buried under the deck recharge overnight at the dock.
When Strater pushed the throttle, the vessel rose quickly onto plane. It performed just like a gasoline outboard, only quieter. In a few minutes, the boat was at the mouth of the Royal River, heading to a point off Littlejohn Island in Yarmouth.
Solar and batteries, but at a cost
Strater nosed the boat up to the solar barge, one of two sites off Yarmouth operated by Nauti Sisters Sea Farm. It’s a small, three-sister enterprise that includes charter tours and oyster tastings. Last year they produced roughly 75,000 oysters.
Nauti Sisters previously relied on floating docks, each costing around $10,000. That didn’t include the cost of moving and storing the floats each winter, $1,000 for a generator and 80 or so gallons of gasoline each season.
Nauti Sister is too small to capitalize the cost of the solar barge, which along with the electric outboard and tumbler is $50,000. But it’s a manageable size to partner with companies looking to refine the design.
“It’s an exciting thing to jump on, electrification,” said Alicia Gaiero, Nauti Sisters’ founder. “We want to be our best and be good stewards. That’s why we farm.”
The 24×8-foot barge was launched last July to replace the floating docks. It’s funded through grants from the U.S. Department of Agriculture, Maine Technology Institute and the Island Institute. Shred also built two similar prototypes for Blackstone Point Oysters, on the Damariscotta River in Newcastle.
Gaiero would like to add an electric work boat to the operation, but it’s not feasible now. She’s making do with two older, 19-foot recreation-style boats to get back and forth to the farms and for tours. She was able to repower one of them last fall with a modern, four-stroke gasoline outboard, but the other boat still has an old-style, polluting two-stroke engine. Even if she could afford to go electric, charging the batteries would be a logistical challenge.
“We’re based on Littlejohn Island and there’s no electric hookup by our dock,” Gaiero said. “We’d have to go up the Royal River or to Chebeague Island for power, and then back to Littlejohn.”
Waterfront charging stations are key
A few miles up the bay, near the entrance to Harraseeket Harbor in Freeport, roughly 2 million oysters are under cultivation at Maine Ocean Farms. Charging is one of the biggest hurdles facing marine electrification, according to Willy Leathers, director of farm operations.
But the farm is about to address that problem, as part of a $1 million project funded in part with a $500,000 U.S. Department of Energy grant, along with other partners. It will pay for two chargers to be installed in Portland and Yarmouth. The project includes a custom-built aluminum workboat from Fogg Boatworks in North Yarmouth and twin 120-horsepower electric outboards.
A separate, smaller, barge project funded by the USDA, The Nature Conservancy and the Island Institute is nearing completion. It will be powered by six solar panels and a small wind turbine. It will include an upweller, a tank system that pumps seawater to raise oyster seed, or spat.
“We started this in 2021,” Leathers said. “It took two years to get through the DOE application phase. We thought funding would stop in January, but it didn’t. But the funding climate is changing. I don’t know exactly what that will mean.”
Maine Ocean Farms will send 350,000 oysters to market this year. With the new electric boat and access to chargers, the company can deliver oysters by water to businesses on the wharfs in Portland. That can eliminate the step of offloading in Freeport and trucking south.
“We make constant efforts to innovate and find efficiencies in what we’re doing,” Leathers said. “If I can reduce workplace noise and emissions, that will have the biggest impact on my employees.”
Leathers stressed that this is a pilot project. He’s anxious to see if the technologies will work as expected and meet the farm’s demands.
“At the end of the day, this is an industrial work environment, “ he said. “It’s not hobby farming.”
Electric Boat Toolkit
Recognizing the potential to expand these practices industry wide, Leathers, The Boat Yard, Shred-founder Planson and other stakeholders recently finalized an 82-page technical report for a $198,750 USDA research grant called Transitioning Sea Farms to Clean Battery Power. It outlined the process that included surveying sea farmers about their power needs, creating various battery-powered solutions for them and analysing the costs and benefits versus gas and diesel power. The work has attracted interest from aquaculture ventures ranging from small oyster farms to large salmon farms.
“Many aquaculture species clean the water as they grow,” the report said. “Processing them with zero-carbon solutions will further enhance their environmental benefits and will lead to a carbon-neutral or carbon-negative supply chain.”
Perhaps the most comprehensive push in Maine for marine electrification is coming from the Island Institute. The non-profit advocacy group has created an Electric Boat Toolkit, an online guide to resources that include funding options, reports, webinars and real-world examples. The group has an online map showing clean-energy projects it has supported, from Portland to Machias. They range from electric motors and solar arrays to shoreside charging stations.
The Island Institute also has partnered with Luke’s Lobster of Portland to detail the total supply chain emissions from harvesting, processing, transporting and selling lobster and crab. Greenhouse gas emission studies for oyster and mussel farming are pending.
“Oyster farms are easier to completely electrify,” said Phoebe Walsh, community development officer at the Island Institute. “They are smaller operations. There’s a short commute to the farm.”
Using money from a private foundation fund, the institute has helped a variety of oyster farms back out of gas and diesel generation. They include $7,500 and $8,000 grants for solar and battery barge installation, the first at Bombazine Oyster Co. in Brunswick; the second at Cranberry Oysters in Cranberry Isles.
The institute is gathering financial data such as return-on-investment and fuel and maintenance cost savings. With federal money at risk, it hopes to make a case for more state support, similar to the heat pump rebate program run by Efficiency Maine.
“There’s no easy answer,” Walsh said. “This equipment is expensive, but if we can show it saves businesses money in the long run, maybe we can get some assistance.”
Research and development for sea farms can also pave the way for battery power in other waterfront sectors, notably lobster fishing. A 2022 study on the feasibility of electrifying Maine’s lobster fleet concluded pure battery power wasn’t ready to meet the energy demands of most commercial lobster boats, which typically are propelled by inboard diesel engines.
“In the near term,” the report said, “we recommend testing a hybrid system, either as a retrofit or possibly with a more efficient hull design for even greater emissions reductions.”
But there’s also a segment of the Maine lobster fleet made up of smaller vessels that are powered by outboard engines and fish traps closer to shore. The latest generation of larger electric outboards and lighter batteries might suit them, Strater said. He’d like to spend a day on the water with some near-shore lobstermen to study their so-called duty cycle.
“That’s the holy grail for electric, commercial workboats,” he said. “Near shore lobster.”
