Ellen: Silent Seafarer

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The fully electric ferry in Denmark is paving the route for a sustainable eco footprint

By Rhonita Patnaik

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Published: Mon 27 Jun 2022, 10:54 AM

In just the past few decades, Denmark has successfully reduced its greenhouse gas (GHG) emissions by half while doubling its economy over the same time. Today, the country has been rated one of the happiest, healthiest, and wealthiest in the world. Adding to that, in the past year, Denmark pledged to cut emissions even further — 70 per cent by 2030, compared to 1990 levels — while still maintaining generous social benefits.

Complementing this vision are the efforts taken by Danish sustainable engineering company Danfoss. Danfoss has supplied electric Editron drivetrains and propulsion motors for the ferry.


In Sønderborg, we set our foot onboard the world’s most powerful and longest ranging 100 per cent electric ferry — Ellen. On a round trip, Ellen travels 22 nautical miles or 40 km and carries the largest battery capacity at sea. Ellen sails without emitting CO2 and operates at 24 per cent lower cost while being 87.4 per cent more energy efficient compared to a new diesel ferry. The e-ferry, powered by Danfoss Editron, is a climate-friendly and valid commercial alternative to conventional counterparts with a complete payback time down to four years. In operation since 2019, Ellen is an excellent example of the future for electric transport: cleaner, greener and more efficient.

Ellen was built as a prototype demonstration project by a private and public partnership or consortia of nine partners under the EU Horizon 2020 programme. An expert in the transportation field and part of the Ellen project, Henrik Hagbarth Mikkelsen, Senior Lecturer, Marstal Naval Academy, Denmark, who helped sepcify the technical during its design phase, said that electric ferries are part of the Danish maritime. He says: “In Denmark, four ferries are fully battery operated on a continuous basis. Of these, some are retrofits on diesel vessels. Besides, a number of harbour buses and smaller passenger ships are fully battery operated as well.”


He added that besides the four fully-electric ferries, additional 10 ferries are hybrids with both battery operation and diesel-engines for peak shaving or peak shifting, which leads to higher energy efficiency and typically savings of 20-30 per cent in fuel consumption. “Four of these are very big ferries operating internationally between Denmark and Germany in the Baltic Sea by the shipping company Scandlines. In 2024, they will add a similar sized full battery-operated freight ferry. This will be the largest to my knowledge.”

Ellen is currently operational between Ærø and Als in Southern Denmark. The Municipality of Ærø) has decided to order two new ferries like Ellen but twice the size and with even higher service speed (around 16 knots or 30 km/h), Mikkelsen added. Speaking about advantages of Ellen vis-à-vis diesel ferries in Denmark, in terms of comfort and engine, Mikkelsen points out a few.

  • Environmental savings: Approximately 2,520 tonnes of CO2 savings compared to a similar new build diesel ferry, according to the evaluation study under the EU Horizon 2020 E-ferry demonstration project. Even without using renewable energy, emission savings are still high due to improved energy efficiency of the fully electric drive train.
  • Economical savings: From the evaluation report it is estimated that operating cost is 24 per cent reduced compared to a similar fossil fuel ferry and energy cost for propulsion has been reduced by almost two-thirds.
  • Impact on nature and people: First, the hull shape of the ferry has been optimised to lower wave and wake issues and lower resistance trough the water. This compensates for the longer range and higher energy density of fossil fuel drive trains and on the trip to Sønderborg, Ellen broke the record of battery operated distance sailing 50 nautical miles or 92 km without charging at any part of the journey.
  • Reduced sound emission: The battery operation is extremely quiet and passengers have rated the comfort most satisfying in surveys conducted.

Ecological investment: Speaking about the investments, Mikkelsen said that the cost of the prototype ferry was $19 million and cost of shore installation and charging infrastructure was $10 million. On top of this came EU project cost, which came to $6 million. However, a new e-ferry of same size and capacity could be ordered for around $15 million today due to falling battery prices and a much more matured maritime industry of power electric components. Also, the shore infrastructure is a one-time expense and could be used by more ferries at the same port, he adds.

Sustainability initiatives: Mikkelsen pointed out. “A lifecycle assessment has been prepared by the Danish Technical University and also the Greek university department CERTH conducted studies on socio-economic impacts. In the design process both alternative building materials for ferries and concerns to scrapping materials and battery second-life options have been investigated.”

Danfoss Editron will apply for Guinness World Record after E-ferry Ellen sails more than 92km on single battery charge, marking a new world record.

— rhonita@khaleejtimes.com


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