It seemed impossible at first, but a German consortium led by Gerd Holbach, a professor at Technischen Universität Berlin (TU Berlin), has shown with a new vessel that fuel cells as a propulsion option will soon no longer be only a theoretical concept. Since 2016 the consortium has been pioneering the development of Elektra, the first hydrogen-fueled tug in the world.
Independent energy systems
The basis of the newly developed hybrid system is the battery package, consisting of 242 DNV-GL approved GO1050 modules with a total capacity of 2.5MWh, delivered by EST-Floattech, as well as three maritime fuel cell systems (NT-PEMFC, 100kW peak power each).
Although the power of the battery and the fuel cells will be used together to power the electric motors, for complete redundancy the two powertrains are entirely independent systems.
“In battery-electric mode, the tug will cover 65km (40 miles) over an 8-hour period before recharging is required.”
After almost two years of construction at the Hermann Barthel GmbH shipyard in Derben and the three-day transfer to Berlin’s Westhafen, testing of this unique, innovative and emission-free push boat can now begin.
The companies BEHALA – Berliner Hafen- und Lagerhausgesellschaft (logistics), shipyard Hermann Barthel, BALLARD Power Systems (fuel cells), ARGO – ANLEG (hydrogen system), Schiffselektronik Rostock (electr. Energiesystem), EST-Floattech (battery system) and HGK Shipping (nautical operation) involved in the development, construction and testing of ELEKTRA as partners.
The ELEKTRA will act as a role model as the first emission-free ship and this energy system is designed in such a way that it can be transferred to a large number of inland and coastal vessel types.
It is not just about the energy supply for the ship propulsion. The push boat has its job in pushing push convoys, but at the same time the crew lives and resides on board. In addition to the main drives, energy must also be provided for the temperature control of the rooms and the wheelhouse, the crew cooks and washes on board and the batteries also have “comfortable temperatures” for efficient operation and a long service life.
All of this has to work with a limited amount of energy carried and without loss of range. The waste heat from the fuel cells is used through consistent water cooling and the rooms are heated by a water-water heat pump, the advantage here is that the ship always has water at temperatures above 0 ° C under the keel.
The use of a self-developed energy management system and a driver assistant support the skipper and logistician in planning the operations and carrying out the transports.
With 750 kg of usable gaseous hydrogen at a pressure of 500 bar on board and a battery capacity of 2,500 kilowatt hours, the ship in the push convoy with the loaded heavy cargo lighter URSUS has a range of approx. 400 kilometers, i.e. in the shipping areas from Berlin towards the Rhine / Ruhr, Hamburg and Stettin we only need one more land station in each case in addition to the Westhafen to supply ELEKTRA with hydrogen and electricity.
The first shore stations for the hydrogen tanks and the charging current in the required output class of 500 kilowatts will be put into operation in 2023 in both the West Harbor and the Lüneburg port of Berlin.
The EBMS department of the TU Berlin has concluded a supply contract for the filling and transport of the tank systems (Multiple Energy Gas Container – MEGC) with green hydrogen until the end of the project period at the end of 2024 with the Mittelelbe / H2 Green Power & Logistics GmbH industrial and commercial park.
The MEGC can be exchanged with the on-board crane and the power connection is made via a loading galley, on which the cables are routed on the land side.
For the ship’s crew, handling the arm-thick cables is very easy and the ship is connected to the charging station in a short time and the pier is free of cables.
The tests will initially take place primarily in the area of the capital region, from 2023 the tests will then also be continued increasingly in long-distance traffic towards Hamburg.
We now have the nautical acceptance by the investigation commission with the journey in different push convoy configurations on the Havel in Berlin and we look forward to the test phases in the project.
In the end we will have learned a lot and we can then also say how future marketable ships in this performance class must be optimally equipped and what the concepts for other ship types and performance classes can look like.
With a total project volume of approx. € 13 million, the project is funded by the Federal Ministry of Transport and Digital Infrastructure (BMVI) with approx. € 8 million and supported by the project management organization Jülich (PTJ) and the National Organization for Hydrogen and Fuel Cell Technology (NOW ) supervised and coordinated.