Very commendably, last month's excellent Interferry 2019 Conference in London featured a session on "The Drive Toward Zero Emission Ferries". I recall remarking to my neighbour that the electric propulsion being promoted in that session was all very well for countries such as Norway, Sweden, Finland, Canada, Tasmania (Australia) and France whose electricity is primarily generated by hydro and/or nuclear power plants. What about the vast majority of the world where electricity is largely generated using coal as fuel?
The harsh reality is that electrification means that, for most vessel operators, their ships would essentially become coal burners if they moved to electric propulsion. Not only that, but the transmission losses associated with electric power mean that even larger amounts of electricity are required before the cables are plugged into the boats. So, in most of the world and for most ferries and other vessels, good old reliable diesel would remain far less polluting and, probably, significantly cheaper than electricity.
I'm the first to admit that, in those lucky countries that are well endowed with nuclear and hydro electricity, electric propulsion can be very practical. Indeed, I have ridden on two electric ferries in France, in Marseille and La Rochelle. They were quiet and smooth and appeared practical but they only operated over very short distances and could be plugged in to the mains at either end of their short voyages. Of course, the fact that their power was nuclear generated plus the provision of, apparently generous, French government subsidies, made them practical.
While chatting with my neighbour in London, I was also thinking of the several flights I had taken to get there. Before boarding each of them, I was assiduously interrogated about any batteries I may have been carrying. No lithium-ion batteries were permitted to be carried in the aircraft holds. This was due to a very reasonable, as it turned out, fear of the risk of them exploding.
Ironically, as I was returning home from Interferry, I learned of an explosion and fire in the lithium-ion battery pack of the Norwegian Ro-Pax ferry Ytteroyningen, a condition apparently known in the trade as "thermal runaway". Fortunately, none of the fifteen people, mostly fire-fighters I gather, admitted to hospital as a result were seriously injured. Apparently, the explosion resulted from a gas accumulation in the ferry's battery room.
The Norwegian Maritime Authority subsequently issued a recommendation that, "all owners of vessels that have battery installations, carry out a new risk assessment of the dangers associated to possible accumulations of explosive gases during unwanted incidents in the battery systems". That, I would imagine, is putting it mildly. Expect a new directive shortly.
Further, Canada's Corvus Energy, which supplied the ferry's battery system, issued a recommendation to operators, "not to sail without communication between the shipboard energy management system and the battery packs." It also advised them of what to do in case of a gas release. Presumably not an easy or cheap solution.
Interestingly, having received a constant flow of press releases from electrification promoters over the past few years, they ceased abruptly by mid-October. It would appear that now is a very good time to "return to the drawing board". I am sure that electric propulsion will eventually have its day in countries that are blessed with nuclear or hydro electricity but, before it does, its promoters will have to convince operators and regulators that their systems are unquestionably safe. There is quite obviously no rush to adopt this seemingly promising new technology and, realistically, there will be no practical place for it in most of the world for some time.