Environmental regulations are constantly forcing carriers to adjust their fuel strategy – so what is the plausibility of electric/hybrid powered container ships? Under what conditions and could those ships travel? Would container terminals need to invest in charging solutions? Perhaps it's only feasible for container ships travelling short distances back and forward between two ports, rather than round-the-world journeys? Anastasia Papadopoulou offers some insight in her latest keynote article.

Electric-powered container ships could work well for shorter and more predictable routes, for example: in liner container shipping, where vessels follow a scheduled service on fixed short routes. Another feasible category would be feeder container ships, operating a limited inland service and also those dedicated to trading in specific areas.

The potential range of electric ships would depend on the capacity of their batteries and the vessels' consumption, which in turn is affected by the weight of the cargo, the hydrodynamic efficiency of the hull, and even, the weather. Shorter routes would be preferred to test the safety of such electric-powered ships and to ensure that the risk of potential battery failure is completely eliminated.

There are many variables involved in establishing the length of a journey for diesel engine powered ships such as age, size, fuel capacity, speed, and consumption, amongst others. For example, the fuel autonomy of a fully laden panamax container ship with 5,000 tons of IFO diesel onboard, steaming at full speed, would be over a month before bunkers are required.

Electric-powered container ships would require fully operational charging facilities and infrastructure in all nearby ports to the ports of dedicated trade. Such facilities require investment from the container terminals and it is debatable whether, even with such facilities in place, electric bunkering can prove to be quick and efficient. Perhaps a more appropriate solution would be solar-powered batteries or a hybrid solution involving electric bunkering in less congested ports.

These ships could perhaps resolve port congestion issues and address ever increasing environmental concerns in port cities.

The electric-powered shipping idea would have to be mature enough in the liner / feeder inland container ships for the technology to be tested on longer routes and larger ships. The container market is now serviced by huge container ships that cannot access small ports, making charging solutions even more complex for such ships. Oceangoing ships often encounter extreme weather conditions and it may be difficult to predict the consequences that such conditions may have on power consumption.

As to the plausibility of hybrid between electric and diesel engine powered ships, we have seen some initiatives in the ferry and passenger ship segment which prove their feasibility for short routes and therefore also for the liner/ feeder inland container ships market also.

However, due to oversupply, owners of small sized container ships are still operating in a depressed market; shipyards and designers have limited incentives to design and build new hybrid ships. The cost of designing and building a hybrid vessel is higher than an all-electric battery powered ship; one needs to consider that two engines are required, each of which is capable of powering the ship, as well as mechanisms controlling the switchover between the two propulsion methods which inevitably leads to an increase in the ship's weight which in turn increases consumption.

This, perhaps, supports a case for the viability of electric-powered ships as a better investment to hybrid, due to higher potential revenues combined with ever decreasing battery cost and thus lower running costs over the vessel's lifetime. Other sectors such as electric cars and trucks are already leading the way with regulations being adopted worldwide to support cleaner technologies.

This article was written for and first published by Container Management Magazine.

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