Hybrid and fully electric ferries underpin German city’s push towards decarbonisation

A major port on the Baltic and one of Europe’s busiest hubs for passenger ships, Kiel wants to be carbon neutral by 2050. To advance these ambitions, the city wants to reduce the carbon footprint of its public transportation, including its commuter ferry operations.

Underpinning the government’s decarbonisation efforts, German tow and ferry firm Schlepp-und-Färhgesellschaft (SKF) has moved towards electrifying its fleet. In August, it began operating the new hybrid-powered ferry Gaarden on the Kieler Fjord, and has ordered four fully electric ferries.

Measuring 32.40 m by 8.80 m, Gaarden is the first plug-in hybrid ferry on the German Baltic Sea coast and, as such, a landmark for the region. Operating as a cycle and pedestrian ferry within the waters of the fjord, the drive train allows it to be powered by generators or batteries within the precincts of the city, lowering CO2 emissions.

Designed for hard work and reliability, the ferry plies the fjord for up to 12.5 hours a day, running a maximum of five 2.5-hour loops. It has a capacity of 300 passengers.

After six months in operation, SKF says Gaarden has done everything expected of it, operationally and sustainably, and the group has since placed orders for four more ferries with the vessel’s builder, the Netherland’s Holland Shipyards. “Gaarden fulfilled its duties and SFK is confident about extending the contract as originally intended,” says SFK chief executive Ansgar Stalder.

And in the next step of a total renewal of SFK’s fleet, fully electric Düsternbrook will start work on the fjord shortly. Effectively a prototype for the three sister ships, all-electric Düsternbrook, at 27.4-m long and 6.50-m wide, will have a capacity of 140 passengers and 60 bicycles.

Holland Shipyard won the contract for Gaarden – and, as it turned out, for four more ferries – after a hard-fought Europe-wide tender among 13 shipyards that was effectively a trial for the design.

The hull of Gaarden is designed for a service speed of 11 knots an hour with minimum water resistance and maximum reliability. “Ferries require one characteristic first and foremost – [they must] sail like clockwork,” says Holland Shipyards.

Batteries and generators were provided by EST-Floattech, a Netherlands- based supplier doing a thriving business in battery technology. In mid-February the group was contracted to deliver 1,260 kWh of battery energy for a Swedish electric ferry destined to start work in Gothenburg in 2022. The power will enable the vessel to operate on fully electric propulsion for up to eight hours a day.

From the first, it was important that Gaarden and subsequent vessels in the fleet can be easily repaired and maintained – that is, without using drydocks which, Holland Shipyard points out, may be far away from the ferry’s area of operation.

Also, the interior was designed to accommodate commuters and tourists, with comfortable seating, a food and drink kiosk and large deck-to-ceiling panoramic windows for sightseeing.

“The ferry will not only transport passengers from A to B but is also equipped for tourist day trips in the Kieler Fjord,” Holland Shipyard points out. The outer part of the fjord, with sandy beaches, is popular with visitors and leisure sailors.

Further underlying SFK’s green credentials, Gaarden will be progressively joined from early 2022 by three sister vessels as SFK works to comply with the city’s determination to be CO₂-free by 2050. Contracts for the construction of the three newbuilds were signed in mid-January, with the first two due to be delivered in February and May 2022 and the third in early 2026.

The vessels will go a long way to meeting the city’s clean-air targets. Although not strictly a fjord, according to geologists, the Kieler Fjord is an ecologically important 20-km long, 7-km wide inlet of the Baltic Sea on the eastern side of Schleswig-Holstein. The city of Kiel forms the terminal of the Kiel Canal that is one of the busiest artificial waterways in the world.

The waters require robust ferries. According to maritime risk management consultancy Risc-Kit, storm surges can spring up in certain conditions, particularly nor-nor’easterly winds, and make for rough sailing. In August 1989, a storm damaged marinas and other infrastructure, with other floods following in 1995, 2006 and, most recently, Storm Axel in January 2017.

A specialist in sustainably powered vessels, Holland Shipyard has a packed orderbook of a dozen fully electric or hybrid ferries. As well as the three ferries for SFK, the group is building two fully electric, double-ended, vehicle and passenger ferries for Boreal, which operates in Norway’s Agder province. Measuring 48.9-m long by 29.80-m wide, the ferries were designed by Wärtsilä and will enter service in H2 2021.

Holland Shipyard walks the talk; not only does the group build climate-virtuous ferries, in late 2020 it delivered a fully electric new dredger to Royal Smals, a family owned Netherlands-based dredging specialist, and will later this year start work on the retrofit of a vessel to run on hydrogen fuel cells.

Clearly, Holland Shipyards and its client SFK look to a cleaner, better future for the ferry industry.