Japan has launched the Mizuumi Maru, the world's first commercial green hydrogen ship that produces its own fuel from seawater using onboard solar panels. Developed by Kawasaki Heavy Industries and the Japan Shipbuilding Industry Foundation, the 8,000-ton autonomous cargo vessel can operate for up to 90 days without port refueling. It features a 1.2-megawatt solar array with 2,400 square meters of perovskite panels from Panasonic, an onboard reverse osmosis system to desalinate seawater, and stores hydrogen safely in magnesium hydride solid-state tanks. The ship completed its first commercial voyage in November 2024, transporting 6,000 tons of automotive parts from Nagoya to Singapore and returning with electronic components, all with zero direct carbon dioxide emissions. The vessel is certified under new Japanese regulations for autonomous green hydrogen shipping, and Kawasaki has received orders for four more ships from Nippon Yusen Kaisha and Mitsui O.S.K. Lines.