Exploring the Cost and Feasibility of Battery-Electric Ships

> The researchers analyzed US-flagged ships less than 1,000 gross tonnage, which includes primarily passenger ships and three types of tugboats.

This is the buried lede. They are excluding basically all cargo shipping.

- Very little of the shipping industry is US-flagged. Most commercial ships sail under flags of convenience such as Panama and Libera, because of their reduced regulations and costs.

- Nobody carries cargo any distance in vessels of less than 1000 gross tons, because that scale would be uneconomical to operate. Modern seagoing cargo ships have about one crew member per 8000 tons of cargo.

It could be the ships they are studying are the most inefficient, and pollute the most near people. Maybe they make the most sense to electrify. It could also be the only ones that can be forced to electrify by law.

Large container ships are pretty efficient and mostly stay away from populated areas.

Several of the diesel ferries that operate from Auckland harbour will be replaced with electric ferries next year and in 2026. Apparently ferries in Auckland carry only 6% of public transport passengers, but account for 20% of the public transport emissions [0].

0. https://at.govt.nz/bus-train-ferry/ferry-services/low-emissi...

Going fast in water takes incredible amounts of power.