52 Megawatts and 40 Knots: Denmark Just Built the Most Powerful Electric Ships Ever, and Speed Is No Longer an Excuse
For years, high-speed ferries seemed like a difficult target for electrification, presenting numerous challenges due to their unique operational demands and the need for significant energy storage. However, with advances in battery technology and a growing commitment to sustainable transportation, electric ferries are poised to revolutionize the maritime industry. As innovative shipbuilders and engineers work tirelessly to overcome these obstacles, we can now confidently announce, electric ferries here we come! These cutting-edge vessels promise to offer a cleaner, quieter, and more efficient alternative, paving the way for a more environmentally friendly future in maritime travel.
Cars could use batteries as an efficient and sustainable alternative to traditional fuel sources. City buses could recharge overnight, ensuring that they are fully powered and ready to transport commuters at the start of each day. Small passenger boats could operate on short routes, offering eco-friendly transit options for local travelers and tourists alike. However, a large ferry carrying hundreds of cars and passengers across open water at more than 40 knots appeared to need too much power, raising questions about the feasibility of relying solely on electric propulsion for such demanding journeys. The energy requirements for a vessel of that size not only involve the propulsion system but also the necessary infrastructure to support such rapid charging capabilities, which may pose significant challenges for the maritime industry.
Denmark Moving forward with Electric Ferries
Denmark is about to challenge that assumption, stepping forward with a bold initiative that promises to reshape perspectives and redefine standards within the region. With its innovative policies and forward-thinking approaches, Denmark aims to demonstrate that conventional beliefs may not hold up against the realities of progress and change. By investing in sustainable technologies and prioritizing social welfare, the nation seeks to set a new example that encourages both collaboration and transformation across various sectors.
Molslinjen, Denmark’s largest domestic ferry operator, is introducing three fully electric high-speed catamarans. Each vessel will use a 54-megawatt-hour lithium iron phosphate battery system and a 52-megawatt propulsion system.
The ferries are due to enter service in 2028 and 2029. They will serve the Aarhus–Odden and Ebeltoft–Odden routes across the Kattegat, a crossing of roughly 70 kilometers between Jutland and Zealand.
Wärtsilä Electric Ferries
According to Wärtsilä, the technology supplier, the vessels will be the fastest and most powerful electric ships to date. They will also carry up to 1,483 passengers and 500 cars.
That combination matters. It shows that marine electrification is no longer limited to slow, short-distance vessels.
Two electric ferries. Two completely different missions.
This project pairs naturally with the small electric ferry we recently covered in the Philippines, which highlights a growing trend towards sustainable and eco-friendly transportation solutions. As we continue to seek innovative ways to reduce our carbon footprint and promote cleaner energy alternatives, this initiative not only enhances connectivity among various islands but also serves as a model for other regions looking to embrace similar technologies. The integration of such electric vessels is expected to significantly lower emissions and operational costs while providing a reliable and efficient mode of travel for both locals and tourists alike.
The M/B Dalaray operates on the Pasig River. It carries about 40 passengers. Its battery stores 160 kilowatt-hours. It cruises at roughly 8 knots.
Molslinjen’s Electric Ferries Catamarans
Molslinjen’s new catamarans will carry 1,483 passengers and 500 cars. Each ferry will use a 54 megawatt-hour battery. That equals 54,000 kilowatt-hours.
In other words, each Danish ferry will carry roughly 337 times more battery capacity than the M/B Dalaray. It will also travel about five times faster.
The contrast is useful. It shows that electrification does not follow one standard recipe.
Instead, the battery must match the mission.
The Pasig ferry does not carry unnecessary range. It serves a short urban route with regular access to shore charging. Molslinjen, by contrast, must cross open water at high speed while carrying a full ferry load.
Therefore, it accepts a much larger battery and a far more powerful charging system.
This is the same principle behind other forms of energy storage. Our thermal energy storage coverage explains why the right storage technology depends on the job. A sand battery stores heat. A grid battery stores electricity. A ferry battery stores propulsion energy.
The goal is not to use the biggest battery possible. The goal is to use the right system for the route.
52 megawatts of electric propulsion
Each Molslinjen vessel will use eight electrically driven waterjets.
A waterjet pulls water into the vessel and pushes it out at high speed. That thrust moves the ship forward. Unlike a conventional propeller, the system places the propulsion equipment inside the hull.
That design offers several benefits for a high-speed catamaran.
First, waterjets support shallow-draft operation. The ferry can operate in relatively shallow water without exposing large propellers below the hull.
Second, the jets provide responsive maneuverability. Integrated steering and reversing functions help the vessel turn, slow down, and dock accurately.
Finally, waterjets can reduce maintenance needs because the propulsion equipment remains protected within the vessel.
Wärtsilä says the propulsion system will divide the available power across multiple jets. That lowers the power density at each individual unit. Properly configured, the system can improve propulsive efficiency while delivering very high output.
Why LFP batteries fit this ferry mission
Molslinjen selected lithium iron phosphate, or LFP, battery chemistry.
LFP batteries use lithium iron phosphate in the cathode. Unlike nickel-manganese-cobalt batteries, LFP chemistry does not use cobalt or nickel in the cathode material.
That choice matters for a ferry that may charge and discharge at high power multiple times each day.
LFP batteries generally offer:
- Strong thermal stability
- Long cycle life
- Lower reliance on cobalt and nickel
- Good performance for repeated charge and discharge cycles
No battery chemistry removes every safety concern. However, LFP chemistry tends to be more thermally stable than several nickel- and cobalt-based alternatives.
That makes it attractive for electric buses, energy storage facilities, commercial vehicles, and marine applications.
The ferry industry still needs strong monitoring, cooling, fire protection, and emergency planning. Battery chemistry helps, but it does not replace responsible engineering.
That lesson also connects to our recent coverage of New York’s large-scale storage build out
. The state now requires supported energy storage projects to meet updated safety codes, emergency planning requirements, and first-responder training standards. You can read related background in our New York battery storage coverage.
The real challenge sits on shore
The most important number in this project may not be 52 MW.
It may be 55 MW.
That is the capacity of the high-power charging system that will recharge each ferry in about 30 minutes.
The charging system must deliver enormous amounts of electricity during a short port visit. To do that, Molslinjen needs medium-voltage shore power infrastructure both on land and onboard the vessels.
Medium-voltage power operates above the low-voltage electricity used in most homes and small businesses. Ports use it to move large amounts of electricity efficiently over larger distances. However, installing that equipment requires new substations, switch-gear
, cables, controls, safety systems, and grid connections.
Therefore, electrifying a ferry fleet involves far more than installing batteries inside a ship.
The port must also be ready.
This mirrors the electric vehicle market. Automakers can build capable electric cars, but drivers still need reliable charging stations. Similarly, shipbuilders can deliver electric ferries, but operators need ports that can provide enough power quickly.
The 30-minute recharge window is especially important. A ferry already spends time in port unloading passengers, loading cars, and preparing for its next crossing.
Molslinjen aims to use that existing turnaround period for charging. In effect, the operator converts refueling time into charging time without adding a separate operational delay.
That is smart infrastructure planning. Charging works best when it fits into a trip that people already make or a stop that a vehicle already requires.
A projected 132,000-ton annual reduction
When all three vessels enter service, the project could cut emissions by up to 132,000 tons of carbon dioxide each year.
That figure comes from the operator and Wärtsilä. It remains a projection because the ferries have not yet entered regular service.
Still, the potential is significant. Three ships on one route could avoid more than 100,000 tons of annual emissions. Multiply that across suitable ferry routes worldwide, and the opportunity becomes much larger.
Ferries are a strong starting point for maritime electrification because their routes are predictable. They leave from the same ports. They travel a known distance. They return to a location with charging equipment.
Container ships and long-distance vessels face much more difficult challenges. They may spend weeks at sea and travel between ports with different infrastructure.
Ferries, however, can build a repeatable energy system around a repeatable route.
Regulation is accelerating the shift
Molslinjen is not acting only because the technology is exciting.
The company faces fast-approaching climate requirements. The International Maritime Organization’s 2023 strategy calls for international shipping emissions to fall by at least 20 percent by 2030 compared with 2008 levels, while striving for a 30 percent reduction.
That deadline adds pressure. Operators must reduce emissions while maintaining reliable service and protecting their business models.
Regulation often moves industries faster than voluntary pledges. New York’s storage safety rules show the same pattern. So do efficiency standards, vehicle emissions requirements, and expanding clean-energy procurement programs.
In this case, compliance pressure meets a technology that is now ready for a demanding commercial route.
Important caveats
The announcement deserves excitement. It also deserves careful reading.
The ferries are not operating yet. They are being built at the Incat shipyard in Tasmania and are scheduled to enter service in 2028 and 2029.
The 132,000-ton emissions figure is projected. Actual results will depend on route schedules, passenger and vehicle loads, weather, charging performance, battery degradation, and the electricity mix used at the ports.
Denmark has a relatively clean electricity system. As a result, the emissions benefits may be stronger there than in regions that rely heavily on coal or oil-fired power.
The 55 MW charging infrastructure will also require major capital investment. Smaller ferry operators may not have the same access to financing, grid connections, shipyards, or technical expertise.
Even so, those caveats do not weaken the central point. They define the conditions needed to repeat the success.
Speed is no longer the excuse
Molslinjen’s project does not electrify every type of ship. It does something more useful.
It proves that a large, fast, commercially important ferry route can use battery-electric propulsion without giving up speed, capacity, or reliable turnaround times.
The M/B Dalaray and Molslinjen’s new catamarans illustrate two distinct approaches within the same narrative. While one catamaran employs a modest battery designed for efficient short urban routes, the other stands out by utilizing a massive battery that powers high-speed transport across open waters. Moreover, the M/B Dalaray showcases remarkable agility, effortlessly navigating bustling city ports, whereas Molslinjen’s vessel demonstrates impressive speed and resilience, making it well-suited for the expansive sea. Consequently, both options cater to different travel needs, reflecting innovation in their respective spheres.
Both work because engineers match the battery to the mission.
That is the broader lesson for sustainable transportation. Electrification is not a single product. It is a design strategy.
The water may be the last major frontier after cars, buses, trucks, and trains. However, these Danish ferries show that the frontier is moving.
When you take a ferry, notice who operates it and what fuel it burns. Ask whether the company has an emissions plan. Public attention matters. Consumer demand helped accelerate hybrid vehicles, and it can help push marine operators toward cleaner service, too.
Acknowledgment
Thank you to Molslinjen, Wärtsilä, and Incat for making the project’s technical details available. Their work helps the public understand how battery capacity, propulsion design, port infrastructure, and commercial ferry operations must work together.
For readers who want to learn more about responsible battery end-of-life management, see our electric vehicle battery recycling coverage.
Sources
- Wärtsilä: Molslinjen cuts CO₂ emissions with fully electric fast ferries
- International Maritime Organization: Cutting GHG emissions from ships
- University of the Philippines Diliman: M/B Dalaray electric ferry
