Passenger ferry and cruiseship operators have been at the forefront of interest to install pollution-free fuel-cell systems.

A 3MW installed-power fuel-cell system is close to being launched by ABB Marine & Ports and Ballard Power Systems, with the most likely use to provide energy for auxiliary or hotel functions on board smaller vessels. But what would 3MW give in terms of propulsion power?

Jan-Erik Rasanen, head of new technology at Finnish ship design and engineering company Foreship, said it could be enough power for a 100-metre-long double-ended ferry with a hotel load of 600kW.

A relatively small cruiseship of 80,000 gt carrying about 2,200 passengers would normally require 40MW of installed power from a diesel engine, but Rasanen said a 30MW fuel-cell system could be sufficient as its parallel-connected units would more easily fulfil redundancy requirements.

Foreship has speculated the capital expenditure of a fuel-cell system could be 1.5 times to twice the cost of a traditional diesel engine.

“To go ahead with an installation today, there would have to be a specific need from the owner — and it would be preferable that they select a primary fuel that can be made from renewables,” he said.

Installation concerns

Although it is theoretically possible, Rasanen added that the biggest problem would be physically fitting a 30MW fuel-cell system in combination with batteries into a ship.

“We are not yet there on the energy density so that you can match a diesel engine,” he added of bunkering with hydrogen — and unlikely to be for 15 years yet.

At a price of $600 per tonne for marine gas oil, Foreship has estimated that the operating cost could be twice as high using natural gas and possibly five times more for hydrogen derived from renewables.

Prices can vary wildly and, although lower now, fossil fuel costs may rise over time with carbon taxing while renewables continue to fall as they have over recent years.

“Owners who were willing to invest early this year are now not in a position to do this," he said. "Give them two more years and I hope they will be back in a position where they can discuss these kind of installations."