EV on H2O?: The Feasibility of Electrifying Maine’s Lobster Fleet by 2050

by John Hagan and Richard Nelson

In 2020, the State of Maine set an ambitious goal of reducing greenhouse gas emissions by 80% by 2050.  This is a call to action for all sectors of Maine’s economy.  To meet a goal this big, we need the creativity and ingenuity of everyone.  Ideas we didn’t think were possible will become reality.

Maine’s 4,600-boat lobster fleet lands $500-$700 million of lobsters each year, some 80% of the value of Maine’s entire fisheries sector.  Fishing, and especially lobster fishing, is not only essential to the well-being of coastal communities, it’s a part of Maine’s heritage.

The fishing industry relies on the use of fossil fuels. Maine’s lobster fleet is powered by relatively carbon-intensive diesel engines.  Fuel can account for as much as 60% of total fishing costs.  Even though fish (including crustaceans) are a low-emissions alternative to land-based protein, the fishing industry is a contributor to global CO2 emissions.

With Maine’s 30-year goal to reduce emissions by 80%, now is the time to understand the technical feasibility of de-carbonizing Maine’s lobster fleet.  Marine propulsion systems are evolving rapidly.  Electric engines are now being used in ferries, but these boats are large and can carry heavy batteries.  Their average trip length is also relatively short.

Our report lays out alternative propulsion systems that could reduce emissions in the lobster fishery.  Maine, with its diverse and capable boatbuilding industry, 3,000 miles of coastline, and a large fishing fleet, is the perfect place to pioneer these new technologies.



Pure EV schematic.  There is no diesel engine, only an electric motor powered by batteries.  The two important questions are: (1) ‘Can current battery technology meet the power demands (duty cycle) of a lobster boat for 7-20 hours at sea?’, and (2) ‘How would the battery system be recharged?’ The answer to the first question is “no.”  It would take too many batteries to run a boat for that long with today’s technology.  The answer to the second question is that we would have to build fast-charging infrastructure to charge boats at the wharf.  But the first question makes the second question moot. Hybrid systems that have a diesel engine on board are more likely to meet the duty cycle requirements of a lobster boat.

Hybrid Serial Propulsion schematic.  A diesel engine and a generator create power that is stored in on-board batteries.  The batteries supply the power to the electric motor connected to the driveshaft.  The diesel engine is NOT connected mechanically to the propeller shaft.  Its sole function is to generate electricity to keep the batteries charged.  If shore power is available, the batteries can be topped off without using the diesel initially on the next day.  The problem is that boats moor at night in Maine and have no access to shore power.

Hybrid Parallel Propulsion schematic.  Either the diesel engine or the electric motor can drive the driveshaft through a gearbox. The diesel engine, combined with a generator, can also recharge the batteries that power the electric motor and other auxiliary functions.  The hybrid parallel system guarantees that the boat can always be propelled by a traditional diesel engine, but also can take advantage of the energy/emissions savings by using the electric motor when operating at slow speeds.  The electric motor can be linked into the propeller shaft by a belt, a gearbox (as shown), or by other means.  If the energy management system is operating at optimum, and depending on the duty cycle (speed, load, etc.) of the boat, emissions and fuel savings might be reduced by 30-40%.

Hydrogen Fuel Cell Propulsion schematic.  On-board hydrogen tanks continuously supply hydrogen to fuel cells, which in turn produce electricity that keeps the battery storage system charged.  There is no diesel engine.  Fuel cells can produce electrical power as long as there is a supply of hydrogen, thus extending the range over a pure-EV system.  Shore-side infrastructure for hydrogen fueling would need to be built.  The hydrogen would need to be “green” hydrogen produced from renewable energy to reduce the boat’s effective emissions.

(Click on image above to download report)

For more information, contact: [email protected]

Report Authors

John Hagan

Richard Nelson


NSBA. 2015.  Review of All-Electric and Hybrid-Electric Propulsion Technology for Small Vessels.  Nova Scotia Boatbuilders Association. Halifax, Nova Scotia, 30 pp.

Kemp, C. and S. Atshan.  2021.  Electric Power Systems for Fishing Vessels: Feasibility, Fuel Savings, and costs.  Kempy Energetics.  46 pp. (link).

Molloy, S. 2021.  Feasibility Study on Moving Towards an Electric Powered Fishing Fleet.  Report for the Fish, Food, and Allied Workers (FFAW).  November 2021. 37 pp.