The high exhaust emissions and the noise levels of diesel ferries were the reason why the port city of Kaohsiung commissioned an electrically-operated ferry from the local shipping company Ting Hai Shipbuilding Co., Ltd. The 25 meters long, 6.50 meters wide and 108 ton ferry offers space for 150 passengers and 46 bicycles. The electric drive with 80 batteries allows for an average travel speed of six knots and four hours of operating time. The charge time is about three hours.

Innovative Decentralized Drive with a High Degree of Efficiency

Baumüller uses the powerMELA drive concept in the ferry, which is a joint development with Sensor-Technik Wiedemann. This decentralized concept of an electric motor and integrated frequency inverter impresses with a compact design. The drive system thus requires minimum installation space and only weighs around 300 kg with the motor, inverter and transmission. Thanks to its innovative direct cooling concept, the motor offers a very high power density and, due to its recuperation capability, i.e. the ability to recovery energy while braking, it meets all the requirements of an efficient system.

In the innovative Baumüller complete solution, the ferry’s two ship propellers are each powered by two powerMELA systems in a dual drive each with 150 kW. The ferry’s operating and on-board network is powered by three parallel-connection lithium ion batteries, which are charged overnight using shore power via the local power grid. During the day, solar cells on the ferry’s roof feed additional energy into the batteries. Although the ship is designed for purely electric operation, it has two diesel emergency units as an additional source of power. This makes it possible to realize hybrid driving profiles as well.

The advantages of the battery-powered ship solution from Baumüller on the one hand lie in the intelligent overall concept based on the many years of experience in the marine propulsion sector and on the other hand in the highly-efficient synchronous motors. The drive system thus achieves a degree of efficiency of over 95%.