Major step forward for fuel cells as IMO approves safety guidelines
It takes power to move a ship. For centuries they relied mainly on harnessing wind but at the end of the 18th century the first steam ships appeared. The first diesel-powered ships using internal combustion engines appeared more than 100 years later, early in the 20th century, while the first nuclear-powered ship started service in 1959.
This puts into context how historic it was when, in mid-September last year, the IMO’s Sub-Committee on Carriage of Cargoes and Containers (CCC 7) agreed draft interim guidelines for ships using fuel cell power installations, adding fuel cells to the short list of energy converters used to power ships.
It took around 10 years of discussion to develop the framework, intended to ensure the safe and reliable delivery of electrical and/or thermal energy through the use of fuel cell technology.
This milestone for ship propulsion received the formal stamp of approval when the Maritime Safety Committee, at its 105th session (20 to 29 April 2022), approved Interim guidelines for the safety of ships using fuel cell power installations.
The goal of these Interim Guidelines is to provide criteria for the arrangement and installation of fuel cell power installations with at least the same level of safety and reliability as new and comparable conventional oil-fuelled main and auxiliary machinery installations, regardless of the specific fuel cell type and fuel. Depending on the fuel used, other regulations (e.g. IGF Code, part A) and provisions (e.g. Interim guidelines for the safety of ships using methyl/ethyl alcohol as fuel) are applicable in addition to these Interim Guidelines.
Major emission reductions & future potential
A fuel cell works like a battery, but one that does not run out: it produces electricity and heat as long as fuel is supplied. According to the Hydrogen and Fuel Cell Technologies Office, part of the US Department of Energy, fuel cells can operate at higher efficiencies than combustion engines and can convert the chemical energy in the fuel directly to electrical energy with efficiencies capable of exceeding 60%. Fuel cells can use a wide range of fuels and feedstocks, and they have lower emissions compared to combustion engines. If running on hydrogen, the only products are electricity, water, and heat, meaning zero emissions.
This makes their attraction apparent in the drive to find new fuels and propulsion systems that can help shipping reduce harmful emissions; both air pollutants like sulphur and nitrous oxides, and CO2.
So, can we expect a rush of ships being converted, or built, to use fuel cells powered by hydrogen now? Maybe not just yet, as there are cost and technical barriers to overcome. So far, fuel cells have been deemed suitable mainly for auxiliary power rather than propulsion for ocean-going ships.
Then there is the question of fuel safety. We have well-established safety provisions for marine diesel fuels and LNG, and interim IMO guidelines for the use of methanol – all of which are potential fuels for fuel cells. But IMO safety provisions for ships to use hydrogen, or ammonia as a hydrogen carrier, have yet to be developed.
CCC has initiated the development of guidelines for the safety of ships using hydrogen as fuel, and MSC 105 gave it the green light to begin work on non-mandatory safety provisions for ships to use ammonia as fuel.