E-ferry · Project

Full-Scale Electric Ferry Proven on 10+ Nautical Mile Island Routes

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Imagine replacing your diesel-guzzling car ferry with one that runs entirely on batteries — like a giant floating Tesla. A Danish island actually did it, building and operating a 100% electric ferry on routes over 10 nautical miles, far longer than any electric ferry had managed before. The ferry uses a massive battery pack charged at 4 megawatts (think plugging in 1,000 home chargers at once) and a lightweight carbon composite body that cuts weight by up to 60% on key parts. It now carries passengers, cars, and trucks between the island of Ærø and mainland Denmark with zero emissions.

By the numbers

50%

Energy savings compared to conventional ferries on the same routes

2,000 tonnes

Annual CO2 emission reduction

41,500 kg

Annual NOx emission reduction

1,350 kg

Annual SO2 emission reduction

2,500 kg

Annual particulate emission reduction

60%

Weight reduction on parts replaced by carbon composite elements

4 MW

Record-breaking high charging power capacity

10.7 Nm

Longest demonstrated electric ferry route (Soeby-Fynshav)

The business problem

What needed solving

Ferry operators serving islands, coastal zones, and inland waterways face mounting pressure from emissions regulations, volatile fuel costs, and community demands for cleaner transport. Diesel ferries on medium-range routes (5-15 nautical miles) produce thousands of tonnes of CO2 and significant air pollutants annually, yet until this project, no electric ferry had proven viable beyond short crossings under 5 nautical miles.

The solution

What was built

A full-scale, 100% electric ferry carrying passengers, cars, trucks, and cargo — demonstrated in daily operation on 10+ nautical mile routes. Key deliverables include the integrated steel hull with electric drive train, carbon composite superstructure (60% lighter), 4 MW shore-side fast-charging system, automated mooring systems, high-energy NMC battery cells, and complete operational readiness including crew training and published timetables.

Audience

Who needs this

Regional ferry operators running diesel-powered short-to-medium routesIsland and coastal municipalities responsible for public ferry servicesPort authorities investing in green infrastructure and shore-side powerMarine battery system manufacturers seeking proven integration designsShipyards looking to offer electric ferry newbuilds or retrofits

Business applications

Who can put this to work

Ferry and shipping operators

any

Target: Regional ferry companies operating diesel-powered routes under 15 nautical miles

If you are a ferry operator dealing with rising fuel costs and tightening emissions regulations on short-to-medium routes — this project built and demonstrated a full-scale 100% electric ferry operating on a 10.7 nautical mile route with energy savings of up to 50% compared to conventional ferries. The design uses carbon composite superstructure elements reducing weight by up to 60%, and 4 MW fast charging enables short port turnaround times.

Coastal and island municipalities

any

Target: Local governments responsible for public transport to island communities

If you are a municipality managing ferry connections to islands and facing pressure to cut CO2 emissions — this project proved the concept on real routes connecting Ærø island to the Danish mainland. Annual emission reductions reached approximately 2,000 tonnes CO2, 41,500 kg NOx, and 1,350 kg SO2. The project delivered everything from crew training to published timetables, showing the full path from concept to daily passenger service.

Marine battery and charging infrastructure

SME

Target: Companies manufacturing or installing marine energy storage and shore-side charging systems

If you are in the marine electrification supply chain looking for proven reference designs — this project installed what was described as the largest battery pack ever fitted in a ferry, with a record-breaking charging capacity of up to 4 MW. The project produced verified prototypes of the integrated electric drive train, onshore and onboard battery systems, and high-energy graphite NMC cells, all tested in real operating conditions.

Frequently asked

Quick answers

What does it cost to convert or build an electric ferry like this?

The project data does not include specific vessel costs or per-unit economics. However, the demonstrated energy savings of up to 50% compared to conventional ferries provide a strong indicator of operational cost reduction over time. Contact the consortium for detailed cost-benefit analysis from their real-world operation.

Can this scale to longer routes or larger vessels?

The E-ferry was specifically designed for medium-range routes and demonstrated on distances of 10.7 and 9.6 nautical miles — significantly beyond previous electric ferry ranges (which were under 5 nautical miles). The 4 MW fast-charging system enables short port stays, which is critical for scaling to busier routes. Scaling to much longer distances would require further battery and charging development.

What is the IP situation — can we license this design?

The consortium includes 11 partners across 6 countries with 7 industry partners and 5 SMEs. IP is likely shared among consortium members under the Horizon 2020 grant agreement. Interested companies should contact the coordinator (Ærø Kommune) or the industrial partners to discuss licensing or technology transfer arrangements.

Does this meet current maritime emissions regulations?

The ferry is 100% electrically powered with zero direct emissions — no CO2, NOx, SO2, or particulates during operation. The project also achieved approval for carbon fibre-reinforced composite modules in the superstructure through material and fire testing, meeting maritime safety regulations. This positions the design well ahead of tightening IMO and EU emissions requirements.

How long did it take from concept to operation?

The E-ferry project ran from June 2015 to May 2020, a five-year timeline covering design, prototype manufacturing, integration, approval, and full-scale demonstration including published timetables and crew training. The project built on a prior Danish ERDF-funded study (Green Ferry Vision) that had already proven feasibility.

What infrastructure do ports need for this?

Ports need shore-side charging infrastructure capable of up to 4 MW to enable short turnaround times. The project developed and installed both onshore and onboard electrical systems including battery layout, architecture, connection, and control systems. An automated mooring system was also installed to support efficient docking.

Is there operational data from real-world use?

Yes. The project reached full-scale operation with published timetables, trained crews, and passenger services running on the Soeby-Fynshav (10.7 Nm) and Soeby-Faaborg (9.6 Nm) routes in the Danish Baltic Sea. Deliverables confirm the final prototype was fully assembled, integrated, and approved for service.

Consortium

Who built it

The E-ferry consortium of 11 partners across 6 countries (Denmark, Germany, Finland, Greece, Netherlands, Switzerland) is heavily industry-oriented at 64%, with 7 industrial partners and 5 SMEs — a strong signal that the project was designed for real-world delivery, not just academic research. The coordinator is Ærø Kommune, the Danish island municipality that actually operates the ferry route, meaning the end-user drove the project from day one. The consortium also includes 2 research organizations providing technical depth. This industry-heavy, end-user-led structure makes the results highly credible for any ferry operator or municipality evaluating electric ferry adoption.

SOFARTSSTYRELSENparticipant · DK
ETHNIKO KENTRO EREVNAS KAI TECHNOLOGIKIS ANAPTYXISparticipant · EL
LECLANCHE GMBHparticipant · DE
DANSK BRAND- OG SIKRINGSTEKNISK INSTITUT FORENINGparticipant · DK
TUCO YACHT VAERFT APSparticipant · DK
DANFOSS EDITRON OYparticipant · FI

How to reach the team

Ærø Kommune (Denmark) coordinated this project. SciTransfer can facilitate a warm introduction to the project team.

Order a report on this consortium

Next steps

Talk to the team behind this work.

Want to explore electric ferry technology for your routes? SciTransfer can connect you directly with the E-ferry team and help assess feasibility for your specific operation.

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