Fuel cell principle



How do fuel cells help reduce noxious emissions?
Unlike conventional engines, fuel cells operate according to the principle of 'cold combustion'. This is a highly efficient electrochemical process without any mechanical wear and tear. Fuel cells come in various configurations that are mainly distinguished by their performance category, their operating temperature and the fuels used.

If the energy carrier is renewably sourced hydrogen, the fuel cell can essentially be operated emission free since all it emits is steam. But diesel or natural gas can also help to substantially reduce emissions. This is due, on the one hand, to their greater efficiency compared to conventional powertrains and, on the other, to the more favourable emissions balance. Fuel cells can replace conventional ship engines for propulsion as well as the auxiliary units required to power other operations.

 in full – by high-temperature, i.e. molten carbonate, fuel cells (MCFC). Deployed in a decentralised manner in several segments across the ship, fuel cell modules in the e4ships2 project can be scaled up to any range required.

e4ships' ongoing scientific evaluations of the ecological, technical and economic results ensures the harvesting of key data for technical optimisation and market activation.


What are the advantages of fuel cells?
In general, fuel cells are characterised by their efficiency and low level of noxious emissions. This eases the strain on the environment and lowers costs in the long term. CCHP systems are particularly advantageous for ships, given their higher energy demands. This applies especially to container ships or cruisers as well as to luxury yachts which also benefit from the fuel cells' ability to operate virtually silently with only a low level of vibration. Fuel cell-powered ferries are completely emissions free, enabling them to operate in ecologically sensitive maritime areas, such as the German Wadden See or mudflats.

What are the current maximum outputs for use on ships? What technologies are used? What is currently regarded as cutting edge?
Smaller ferries or excursion boats have an output requirement of somewhere between 100-300 kW. Currently, this can be met by proton-exchange fuel cells operated at low temperature (LT PEM). Super yachts, container and cruise ships often have output requirements in the megawatt range. These are met – in part or in full – by high-temperature, i.e. molten carbonate, fuel cells (MCFC). Deployed in a decentralised manner in several segments across the ship, fuel cell modules in the e4ships2 project can be scaled up to any range required.

e4ships' ongoing scientific evaluations of the ecological, technical and economic results ensures the harvesting of key data for technical optimisation and market activation.
Which ships are the new technologies best suited to?
Depending on the capacity required, fuel cells can be used on a variety of ships. High-temperature fuel cells with a capacity in future of up to 1MW lend themselves to onboard power generation for larger ships, such as cruise and container ships. Also, for reasons of comfort – not least their low vibration and noise levels – for luxury yachts.

Using them to supply power to auxiliary systems, especially when the vessel is in the harbour, can considerably improve air quality. At sea, considerably fewer emissions translates into a significant reduction in pollution for coastal areas along the shipping routes. Fuel cells are already more effective, but combining high-temperature fuel cells with CCHP marks a step up to a completely different level compared to today's energy supply systems. Where needed, any heat generated can also be harnessed for cooling purposes, such as air conditioning, for example.

Smaller passenger ferries or excursion boats up to 300 kW can, for instance, be powered exclusively by low temperature fuel cells; e.g. by integrating fuel cells into a hybrid system buffered with additional high-power batteries.

How high is demand on the part of shipyards and shipping companies? What advantages do fuel cells offer them?
Fuel cells are efficient, quiet and generate few emissions. With more and more coastal zones and port areas now operating under strict environmental regulations (SECA, ECA), it is important to develop future-proof, eco-friendly technologies for this sector. Moreover, in the long term, the use of fuel cells in luxury yachts as well as in container and cruise ships has the potential to reduce their operational costs.


Another key aspect, especially for passenger ships, is that fuel cells make for a virtually silent shipping experience with hardly any vibration. Fuel cell-driven ferries also offer a quiet and, what is more, zero-emission option for moving from A to B. This allows ferries to operate in ecologically sensitive marine areas where they could potentially boost regional tourism.


Reputable German shipyards, shipping companies, leading fuel cell manufacturers and classification societies are backing the e4ships2 project precisely because it gives them an opportunity to test and hone these technologies.  Today already, we are repeatedly asked to employ this technology on other ships, such as mega yachts. Based on the findings from the e4ships2 cluster projects, shipping companies’ demand for these innovations is definitely set to grow.