Geir Bjorkeli, chief executive of Canadian-Norwegian marine ­battery specialist Corvus Energy, believes the electrification of shipping depends on the much larger automobile industry for efficiency and scale.

Bjorkeli holds out hopes for ­Norwegian battery cell manufacturing start-up Freyr to cut the cost and carbon footprint of marine batteries, using northern Norwegian hydropower.

He also remains optimistic for big boxships as a market, even after AP Moller-Maersk turned lukewarm.