Concept Fuel Cell

How do fuel cells reduce harmful emissions?

Unlike conventional motors, fuel cells work on the "cold combustion" principle, a highly efficient electrochemical process which causes no mechanical wear and tear to components. A number of different fuel cell system designs are available; they differ mainly in their performance class, operating temperature and the fuels used.

If hydrogen from sustainable sources is used as energy provider, operation of the fuel cells is virtually emission-free, only water vapour is emitted. If diesel or natural gas are used as fuels, emissions can be substantially reduced thanks to a higher level of efficiency than other drive systems and also because of a more favourable emissions balance. Fuel cells can replace both conventional ships motors and also auxiliary aggregates for supplying subsidiary consumers.
For what kinds of ships are the new technologies particularly well suited?

Fuel cells can be used in many kinds of ships, depending on performance requirements. High-temperature fuel cells, which in future will have an output of up to 1 MW, are suitable as sources of on-board energy for larger vessels such as cruise ships and container ships and also, for reasons of comfort, because they are so quiet, for mega yachts.

Their use as a supply system for auxiliary aggregates, especially while the vessel is in harbour, can lead to a considerable improvement in air quality. When used at sea, the much lower levels of harmful emissions are of particular benefit to coastal marine areas.

As well as being basically more efficient, the employment of high-temperature fuel cells can also substantially boost efficiency in comparison with today's energy supply systems through the use of power and heat cogeneration. In some cases the waste heat produced can be used for cooling, in air-conditioning systems, for instance.

Smaller passenger ferries or excursion ships up to a performance class of 300 kW can obtain their entire drive energy from low-temperature fuel cells, for example. One concept of this type is the integration into a hybrid system backed up additionally by high performance batteries. The steamers used on Hamburg's Lake Alster are examples of this.

What advantages are there?

The use of fuel cells means high efficiency and low levels of harmful emissions. This is good for the environment and reduces costs in the long term. Providing heat or refrigeration through power and heat cogeneration is particularly advantageous for ships with high requirements in these areas, such as container ships, cruise ships and mega yachts, whereby the latter profit especially from the quiet, low-vibration operation of fuel cells. Fuel cell powered ferries operate with zero emissions and can thus be used in sensitive waters, such as tidal mud flats. 

How is demand from shipyards and shipping companies? What advantages would fuel cells bring them?

Fuel cells are efficient, quiet and low-emission. As coastal zones and port areas are increasingly becoming subject to stringent environmental regulations (SECA, ECA) it is important to promote the development of environment-friendly, forward-looking technologies for these areas. The use of fuel cells on board mega yachts, container ships and cruise ships also offers the potential for long-term operational savings. Another important aspect, for passenger ships in particular, is the quiet, low-vibration operation of fuel cells.

Ferries which use fuel cell drives also offer quiet, zero-emission operation. They can be used in ecologically sensitive waters and offer potential for the development of regional tourism.

This is why well-known German shipyards and shipping companies have joined forces with manufacturers of fuel cells and the classification organizations in the e4ships project to test and further develop these technologies. Already today there are repeated enquiries about the use of fuel cell technology on other ships such as mega yachts, but demand from shipping companies can only be expected to really take off when the results of the e4ships demonstration project are available.

By what time could the use of fuel cells become a widespread reality on board ship?

All the ships being used in the e4ships project are commercial vessels. These are development projects, however, even though they are taking place in real, every-day conditions, because the integration of this technology into shipping vessels is still a very new idea. The experience gained from the e4ships project will certainly make a major contribution to collecting the necessary operational  experience and discovering areas of potential optimization for series production.

Widespread use of fuel cells on ships is not to be expected before 2020, however.

What is the maximum performance currently possible in use on ships? What technologies are used for it? What is the current technological state of the art?

Smaller ferries or excursion ships require a performance of between 100 and 300 kW; this can currently be provided by proton exchange fuel cells in the low-temperature range. The 'Alsterwasser' has two 48-kW fuel cells, for instance.

The power requirement of mega yachts, container ships and cruise ships is often in the MW range. High-temperature fuel cells (MCFC) with a performance of up to 500 kW are needed to partially or fully meet this requirement. As part of the e4ships project, the consortium plans to employ more powerful fuel cells (1 MW) in the near future. It is planned for these to be placed in segments in several parts of the vessel.

Thanks to ongoing scientific evaluation of its ecological, technical and scientific results, e4ships will ensure that important data for technical optimization and market preparation have been obtained by the time the project ends in 2014.