Shape up or ship out: How to decarbonise marine craft
When it comes to zero-emission transport, most of the world’s attention has been focussed on cars and trucks. That is inevitable, as we see cars and trucks everyday so we are more aware of the environmental damage they do. However, marine is also a major source of pollution: 940 million tonnes of CO2 annually, which is at least 2.5% of the world's total CO2 Emissions¹.
As with cars and trucks, there is no single zero-emission alternative to diesel powered ships. The very small tenders can go battery electric, but batteries have even more issues at sea than they do on land, because it takes a lot more energy to push a boat through water than drive a car through the air. The figures are startling: if you are happy to pootle at just 5 knots, a 50 kWh battery pack will take a small pleasure craft 50 nautical miles, but if you want to impress your friends at 20 knots, a 70 kWh battery pack will take you just 14 nautical miles². For reference, a typical 50 kWh electric car will travel about 200 miles in normal use³.
Clearly, any boat too big to be towed behind a car is not going to work as a BEV, and then only for short duty cycles. Container ship operators are looking closely at ammonia, which is effectively hydrogen in liquid form. It is zero emission, but ammonia is nasty stuff – in small quantities it smells of manure and, in large quantities, it is toxic and corrosive, causing burns to the skin and lungs. Crew will need special training, and there are question marks over its use in passenger boats – an ammonia spill would be very serious.
Hence there is a lot of focus on gaseous hydrogen. While hydrogen would not be ideal for the largest ships (the tanks for an ocean voyage would be unfeasibly large), it gives sufficient range for inshore use. Like a hydrogen fuel cell car, the range of a hydrogen fuel cell boat is basically the same as a petrol or diesel equivalent. So, as Viritech starts to extend the application of its enabling hydrogen powertrain technologies, its latest project is “marinising” (the technical term for adapting a powertrain for use on water) a hydrogen fuel cell powertrain for boats and yachts.
Marinising car engines is a very common process – everything from the original Land Rover’s diesel engine to the Lamborghini V12 has been adapted for use in boats. The same principle can be applied to a fuel cell: it is generating electricity for use by an electric motor, and is not directly affected by what the motor is propelling (car, boat, stationary generator etc.)
The first fuel cells to be type approved for marine applications appeared in 2022, which means now is the perfect time for Viritech to be developing its marine solutions. Viritech will be making a major announcement regarding its 240KW and 360 KW fuel cell powertrains for trucks next month, and this size of powerplant is ideal for a huge range of hydrogen-powered vessels up to 200 tonnes or more.
motorboats
yachts
catamarans
passenger ferries
fishing boats
commercial shipping
Both leisure and commercial shipping can be transformed by fuel cell propulsion:
For the leisure sector, the whole point is relaxation on the water. There is probably no market where eliminating the noise and smell of an internal combustion engine is so valuable.
For commercial shipping, fuel cells offer the first viable opportunity to use zero-emission marine vessels and there is growing evidence that marine operators feel under pressure to display their green credentials to their customers – e.g. ferry operators, can hardly use diesel engines to transport passengers between urban low emission zones, or carry boatloads of electric vehicles.
For over a century, the choice has been between the romance and tranquillity of sail, or the security and predictability of engines - Viritech hydrogen powertrains will soon offer mariners the best of both worlds…