Electric Passenger Ship Completes Range Test on Lake Constance
On July 10, 2025, the electric solar passenger ship "Insel Mainau," designed and built by Ampereship GmbH, completed a range test on Lake Constance. During a 19-hour continuous journey, the all-electric catamaran covered exactly 211.3 kilometers on the lake, with a remaining battery capacity of 20 percent. The ship was back in regular operation the very next day.
The 300-kilometers mark would have been possible in a test designed exclusively for range. Another record journey is already planned for next year in order to be able to implement the data obtained on the currents in Lake Constance and the maximum energy efficiency of the ship.
According to the shipping company Bodensee-Schiffsbetriebe GmbH (BSB) this will be the longest emission-free journey on the water with an all-electric passenger ship to date.
BSB commissioned Ampereship, a sister company of Ostseestaal GmbH & Co. KG, with the design and construction of the 30-meters-long and eight-meters-wide all-electric catamaran in 2021.
The energy concept of the "Insel Mainau" passenger ship has set new standards in shipbuilding. The Stralsund specialists developed their own control and optimization software and integrated it into the system. In addition, a magnetic mooring system and, for the first time, bifacial (two-sided) solar modules, a development of the ISC Konstanz e.V. (International Solar Energy Research Centre), were used, which can generate renewable energy on their front and rear sides.
Since the middle of the last decade, Ampereship has developed into one of Europe's leading manufacturers of electric solar-powered ships for professional inland shipping. Recently, Hafenprojektgesellschaft Helgoland mbH commissioned Ostseestaal and Ampereship with the development and construction of a fully electric, ocean-going ferry at the start of 2025. The so-called dune ferry will connect the German North Sea island of Heligoland with the neighboring island of Düne.
The lightweight aluminum hull of the dune ferry has now been completed. It has been optimized in terms of flow technology and ensures high energy efficiency and a long service life. In addition, the hull can be 100 percent recycled.
