Green Water Taxi




720.000 Euro

Sponsored by:


The fuel consumption per cargo unit and/or passenger is particularly high on small water transport vehicles, and "economy of scale" has an unfavourable effect. A global view shows that small-scale shipping on coasts and between islands is an important pillar of economic and social development.

While in the leisure sector many different types of sailing propulsion are combined with other forms of propulsion, e.g. as motor sailers, this development has not yet been observed in commercial small-scale shipping.

Video: Green Water Taxi - MariGreen

In the "Green Water Taxi" project, a concept vehicle was developed to transport passengers and small loads flexibly between the mainland and islands. An electric hybrid drive with additional wind power support ensures operation without additional fuel in short-distance traffic. A prototype of the vehicle was built in the project, which allows the testing of different wind drive systems with universal mounts.

The use of hydrogen (H2) is considered a key element in the design of the energy turnaround.

Particularly in the north of the Netherlands and Germany, where renewable energy is increasingly being generated, the use of hydrogen as an energy carrier is becoming increasingly important.

The H2Watt project offers a platform for the realization of various innovation projects for the implementation of hydrogen. The focus is on processes and systems for the use of hydrogen in terms of production, storage, mobility and heating systems. The initial projects include a residential quarter, the Borkum island railway and a water taxi.



The fuselage shape was optimized for half gliding, therefore the PFH shape (Parametric Fast Hull) was chosen. The shape and the optimal distance between the two hulls was calculated numerically and validated in the tow tank. For this purpose the model was built at the University of Emden/Leer.

For the prototype, two auxiliary wind propulsion systems were developed in the Department of Maritime Sciences. On the one hand, a small Flettner rotor was developed and built, which is powered by a battery. On the other hand, a free-standing carbon mast was built, on which a cloth sail is rigged. On board the GWT prototype up to two wind propulsion systems can be tested and compared simultaneously (one system on each hull).

If the wind is not sufficient for the operating speed, the GWT prototype can be operated with two electric outboard motors and battery system.

The finished prototype could be presented to the public at the final conference of the MariGreen project.


The MariGreen project was funded by the European Regional Development Fund (ERDF) as well as by national co-financing from Germany and the Netherlands within the framework of the INTERREG V A programme Germany-Nederland and coordinated by MARIKO GmbH and FME.

Further information about the project can be found here.

Contact person

Prof. Michael Vahs
phone: 0049 (0)491 92817-5022
e-Mail: michael.vahs(at)