There are a lot of moving parts to designing a ferry system, and the boat itself is just the one that floats. Ferries, and particularly commuter ferries, are part of global transportation networks. And in today’s world, those networks need to be green. It usually means electric. In places where electricity is already green, whether wind, solar, hydroelectric or nuclear, the construction of a fully electric ferry as soon as it is put into service is already technically feasible for increasingly long journeys.
Danish E-ferry Ellen has been operating successfully for about two years now on a 22 mile long route. Although it is not the first E-Ferry in the world (this credit goes to Ampere in Norway, which entered service in 2015), it was built under the EU’s Horizon 2020 program, which means that much of the documentation on the project is in the public domain.
When designing a fully electric ferry, the charging infrastructure is an important part of the equation and involves a significant investment. When all the parts of an all-electric ferry aren’t there yet, a hybrid solution probably makes sense. What no longer makes sense is to make a significant investment in a conventional fuel vessel without devising a path to a future conversion / refurbishment to an electric or hybrid solution.
At this point, some readers may jump up and down shouting “hydrogen, hydrogen” and “fuel cells”. That’s a topic for another day, but something to consider is that, at the moment, green hydrogen is in the more distant future than green electricity.
With these thoughts in mind, let’s take a look at some recent projects, starting with the Ellen.
Operating between the Danish islands of Ærø and Fynshav, the vessel is less than 60 meters long and approximately 13 meters wide. This ferry travels at speeds of 12 to 12.5 knots and is capable of carrying 198 passengers in summer, this capacity dropping to 147 in winter. It can also carry 31 cars or five trucks on its open deck.
With a battery pack with a capacity of 4.3 MWh, at the time of construction the largest installed for maritime use, it is the first electric ferry not to have a back-up generator on board.
Danfoss Editron was selected to provide the fully electric transmission. The Editron system consists of two 750 kW propulsion motors and two 250 kW thruster motors, both driven by permanent magnet technology assisted by synchronous reluctance and controlled by DC / AC inverters. Danfoss Editron also supplied the vessel’s power management system, providing full automated power and load control on board. In addition, the company delivered the shore charging station and the charging arm for the battery.
Compared to a similar modern diesel ferry, Ellen annually saves around 2,520 tonnes of CO2, 14.3 tonnes of NOX, 1.5 tonnes of SO2, 1.8 tonnes of CO and half a tonne of particulate matter. The E-ferry is loaded from the local grid on Ærø Island, whose electricity demand is entirely wind-powered.
Ellen offers a propulsion system efficiency that reaches 85% from grid to propeller. This is more than twice as efficient as a conventional diesel engine ferry (propeller tank) and has resulted in a 20% reduction in travel time compared to the diesel powered ferry it replaced. The E-ferry consumes around 1,600 kWh per round trip, which is better than predicted in preliminary studies.
Calculations show that the high initial investment costs for the construction of the E-ferry will be offset after only five to eight years of operation. These calculations take into account the cost of the charging station and the possible need to replace the battery pack twice during the life of the ferry. Quick payback means the operator will save between 24% and 36% in operating costs compared to operating a diesel or diesel-electric ferry for the remainder of the estimated life of the ferry, which is 30 years old.
Gees Bend ferry
While Ampere and the Ellen made headlines, a fully electric ferry has been in service in the United States since April 2019 when, after its conversion at the Master Marine shipyard in Bayou la Batre, Alabama, the historic Department of Transportation ferry Gee’s Bend Alabama (ALDOT) has returned to serve as the first zero-emission electric passenger / car ferry to the United States.
The 95-by-42-foot Gee’s Bend ferry was built in 2004 with diesel propulsion. Operated by HMS Ferries on behalf of ALDOT, the 15 vehicle / 132 passenger ferry operates on the Alabama River between Camden and Boykin, Ala.
The conversion was funded by a grant of $ 1.09 million from the United States Environmental Protection Agency, as well as a matching $ 765,350 from ALDOT. Seattle, Washington, naval architecture and naval engineering firm Glosten provided the concept through contract design and shipyard technical support for the project, which was managed by HMS Ferries and HMS Consulting.
Marine Interface Inc. of East Northport, NY, integrated the new electric propulsion system with support from American Traction Systems, Fort Myers, Fla. (Power conversion) and Spear Power Systems, Grandview, Mo. (batteries) . Cochran Marine, Seattle, Washington, was responsible for the onboard and shore charging stations.
Skagit County E-ferry
Recently Glosten worked on what may be the first mew build battery-powered electric ferry in the United States: an all-electric replacement, the 40-year-old diesel. Guèmes which operates on the 5/8 mile road that separates Anacortes, Washington from Guemes Island.
The replacement ferry will be double-ended with a three-level deckhouse and will accommodate four lanes of vehicles, including road approved trucks and emergency vehicles. The challenges associated with mixing cars and passengers were addressed by keeping passengers and vehicles separate throughout the journey; it also improves scheduling efficiency by eliminating delays when switching between car and passenger loading. In addition, the battery-powered electric propulsion system will significantly reduce the noise production of ships, which means passengers can enjoy a quieter ride.
According to Glosten, the vessel will experience a 50% reduction in operating costs compared to its diesel-powered predecessor and produce virtually no emissions during its crossing. Glosten analyzed the route, terminals and utility infrastructure and found that billing once during each round trip was feasible, reliable and minimized the cost of the project.
A request for proposals for electrical integrators to provide the ship’s onshore electrical systems and automated charging socket for the ship was closed last month. Once the proposals have been analyzed and the supplier selected, the way should be opened to prepare a proposal on which the shipyards can bid.
Ottawa Road ferries
In the meantime, what will be the first fully electric highway ferry to operate in North America has arrived in Canada from the Damen Galati shipyard in Romania. Commissioned by the Department of Transportation, Ontario, Canada, the 68 meter long Amherst Islander II and 98 meters long Wolfe islander iv are equipped for fully electric operation, but also have two diesel generators installed to allow full hybrid and diesel propulsion for maximum redundancy.
The delivery of the vessels marks the completion of the first of two stages of the project. The second step, which is well advanced, is the installation of the facilities that will allow ships to use shore power provided through integrated dock loading and mooring systems.
Damen chose Leclanché, based in Switzerland, to build and supply two fast charging stations and support the electricity storage systems on Lake Ontario. The agreement with Leclanché’s Stationary Solutions group provides the complete charging infrastructure.
Both are powered by Leclanché’s Marine Rack System, certified by Bureau Veritas, under previous contracts with the Leclanché e-Marine group. the Amherst Islander II (Damen 6819 E3) has a Leclanché battery system with a capacity of 1.9 MWh and produces no emissions. It will carry up to 42 cars and 300 passengers at speeds of up to 12 knots and connect the mainland port city of Millhaven, Ontario, with Stella on Amherst Island. The biggest Wolfe islander iv has a Leclanché battery system of 4.6 MWh and can transport twice as many passenger vehicles as the Amherst Islander—83 — plus 399 passengers. He too will sail up to 12 knots.
Leclanché claims that its internal capacity to provide both the battery energy storage system to power maritime vessels and the onshore charging and storage system, powered by grid or increasingly renewable energy sources. more profitable, sets it apart from other suppliers. .
For port regions unable to install a fixed shore energy storage system, Leclanché is working on a mobile charging station option, essentially a floating e-Barge with a fast charge storage system on board.
Ontario ports and port systems will be equipped with a Leclanché 3.0 MWh (BESS) battery energy storage system located in port structures. The BESS, which will be charged by the port network, is connected to the ferry charger via 1800 kW DC-DC converters. These “buffer stations” will be protected by a fire extinguisher system using running water along the battery racks and behind each battery module. The backs of each module have an opening allowing water spray to enter in the event of thermal events. The batteries were designed to charge each vessel up to 7,850 times per year or more than 78,500 times during their expected 10-year life.
Crossing time between ports will be just 20 minutes and Leclanché’s high power DC-to-DC fast charging system will allow e-ferries to ‘refuel’ in just 10 minutes at each port.