DENMARK: How much does electrification influence island living for dwellers and holidaymakers? Every day, when it comes to mainland connection! Molslinjen, as Denmark’s largest domestic ferry operator, is showing how, with the launch of two identical, 100% electric ferries. The first ferry, Nerthus, is now in service on the Alslinjen route, with its sister vessel, Tyrfing, serving the Samsølinjen route. As a result, the expected reduction in CO2 emission is 10,000 tons annually, for both routes combined.
These are the largest electric ferries in Denmark and are equipped with a complete shore-to-ship power solution from Danfoss, for quieter, cleaner, and more economical transit on their routes.
Building on a long-standing partnership, Molslinjen selected Danfoss’ cutting-edge iC7 drive technology to power this new era of emission-free ferry travel. This case story explores how Danfoss iC7-Marine and iC7-Hybrid drives provide highly efficient, reliable power for both onboard battery propulsion and onshore charging.
The challenge: A seamless shore-to-ship power ecosystem
For Molslinjen, the primary challenge was to create a seamless, powerful, and efficient charging and propulsion ecosystem for its new battery-powered ferries
This involved two critical components: managing the high-power charging process from the shore to ensure rapid turnaround times, and efficiently converting the battery’s DC power for the AC electric ferry propulsion motors on board. A service agreement leveraging services such as DrivePro® Preventive Maintenance ensures optimal uptime in the long term. The entire system must be exceptionally reliable to maintain demanding ferry schedules and ensure grid stability at the port.
To make a 100% electric ferry a success, you need an extremely reliable system and the highest possible power conversion efficiency Every kilowatt counts. We needed a complete solution that could handle the significant power demands of fast charging without disrupting the local power grid. We needed a partner who could deliver a robust, end-to-end solution.
The solution: Danfoss iC7 drives for onboard and onshore power
Danfoss delivered the ideal end-to-end solution, utilizing its latest drive technology for both the vessels and the shore-side infrastructure. The ferry's batteries can be charged in 23 minutes and use approximately 1,000 kWh energy per trip.
- On board the ferries: A combination of liquid-cooled Danfoss iC7-Marine and iC7-Hybrid modules form the core of the propulsion system. These compact modules manage the power flow from the on-board battery systems to the motors with market-leading efficiency (over 98%) and the robust reliability demanded by the harsh maritime environment.
- Onshore vessel charging stations: Intelligent Danfoss iC7-Hybrid power converters are the key component in the automated charging systems located at the ferry ports in Ballen, Kalundborg, and Fynshav. These AC-DC converters ensure a fast, stable, and grid-friendly charging process, capable of replenishing the ferry’s batteries during brief port stays.
The iC7 series provides a complete shore-to-ship power solution. By using our drives for both the onshore charging and the onboard propulsion, we create a perfectly harmonized and highly efficient system. It provides the grid-friendly technology Molslinjen needs for stable charging and the rugged reliability required for maritime operations. This integrated approach future-proofs their investment in fleet electrification.
The outcome: A partnership driving decarbonization
With the new electric ferry, Molslinjen expects to emit 6,000 tons of CO2 less per year for the route between Kalundborg and Samsø alone. With both ferries - Nerthus and Thyrfing - in service on their respective routes, the expected saving is 10,000 tons CO2 annually.
The decision to select Danfoss for this landmark project was built on a foundation of trust and a history of successful cooperation. Danfoss has been a key supplier for Molslinjen for many years, providing reliable drive solutions for numerous other vessels in their fleet.
“Our long-standing relationship with Danfoss gave us the confidence to embark on this ambitious project together,” explains Hans Henrik Simonsen. “We know their products are reliable, and we know their team provides the expert support needed to integrate these advanced systems. This partnership is instrumental in our decarbonization journey.”
This collaborative approach, involving Cemre Shipyard and system integrators Can Makina and Soft & Teknik, ensures that Danfoss is not just a supplier but a central partner in delivering complex, large-scale green marine projects. The performance of Nerthus and Tyrfing shows how strong partnerships and innovative technology can help pave the way for a sustainable, emission-free future in maritime transport. And for island residents, the result is a more economical and comfortable connection to the mainland, with a minimal carbon footprint.
