A Chinese electric cargo ship with 19 megawatt hours of batteries is completing trials, combining large-scale energy storage and automation.

source https://www.techradar.com/pro/definitely-not-your-usual-ev-china-begins-sea-trial-for-worlds-largest-electric-ship-ning-yuan-dian-kun-is-longer-than-a-football-field-weighs-10-000-tons-and-uses-10-container-batteries-with-a-total-19mwh-capacity