At long last, cargo ships run on electric currents. Here’s why it matters

In Jules Verne’s classic Twenty Thousand Leagues Under the Sea, Captain Nemo’s futuristic submarine, the Nautilus, is battery-powered. Electric shipping has remained science fiction ever since. That might be about to change, though.

The Ning Yuan Dian Kun, an electric container ship capable of carrying 740 20-foot-equivalent units (TEUs),was delivered earlier this month. Its ten containerized batteries hold as much charge as 380 Tesla Model 3s, and can either be swapped at port or charged from shore-based cables.If you follow the shipping industry, 740 TEUs might seem pretty paltry. The size record is currently held by the MSC Irina, launched in 2023 and carrying 24,346 units, almost 33 times as many as the Ning Yuan Dian Kun.

Until batteries compete on that scale, they can be safely ignored.Well, not quite. While mega-container ships are the workhorses of global trade, essential for connecting major ports such as Shanghai, Rotterdam, Long Beach and Singapore, they’re not for every harbour. Their sheer size excludes them from the thousands of smaller docks that still take container deliveries.

Much of the work of the biggest freight hubs comes not from unloading metal boxes to roads and railways, but sorting them onto smaller feeder vessels for delivery to lesser ports.Many of these feeders are a lot more diminutive than you’d think. Just over half the global container fleet is below 3,000 units, the generally accepted upper limit for this kind of vessel. The average size of all the ships that docked at ports during 2023 is 3,618, according to the United Nations trade and development agency.