Mitsui O.S.K. Lines Ltd. completed the first hybrid car carrier, the Emerald Ace, at the Mitsubishi Heavy Industries Ltd. Kobe shipyard in Tokyo.
The ship, which can hold up to 6,400 standard passenger vehicles, was designed to generate zero emissions while berthed. It is equipped with a hybrid electric power system that combines a 160-kW solar generation system with lithium-ion batteries that can store 2.2 megawatt hours of electricity. Conventional power generation systems use diesel generators to supply on-board electricity while berthed.
Electricity is generated by the solar power generation system while the vessel is under way and stored in the lithium-ion batteries. The diesel generator is shut down when the ship is berthed, and the batteries provide all the electricity it needs, resulting in zero emissions at the pier.
The development of the Emerald Ace was subsidized by the Ministry of Land, Infrastructure, Transport and Tourism as a project to help reduce CO2 emissions from oceangoing vessels, and received support from Nippon Kaiji Kyokai as a cooperative development project to reduce greenhouse gases produced by ocean shipping operations.