Zinus, Corvus Energy, Shell and Kirby Inland Marine power US' First Plug-in Hybrid Electric Inland Towboat

Maritime Battery Forum members Zinus, Corvus Energy and Shell in collaboration with vessel owner/operator Kirby Inland Marine and others power the first hybrid inland towboat in the United States, the Kirby Green Diamond

Photo caption: The Kirby Inland Marine Green Diamond hybrid diesel-electric inland towboat

The first-of-its-kind vessel was constructed by San Jac Marine, Kirby’s shipyard in Channelview, Texas. Another Kirby company Stewart & Stevenson Manufacturing Technologies designed and installed the power management, control and propulsion systems.

Propulsion is provided by two 575 KW Danfoss electric motors that can be driven either by the Corvus Orca series battery system, which provides 1243 KWH of power, or, if needed, onboard Caterpillar generators.

A Shell-owned Zinus charging system will be used for dockside charging of the battery system, allowing the vessel to complete trips within the Houston area without using its generators, Kirby said. Shell Energy Solutions will provide electrical power matched 100% by Green-e certified renewable energy certificates to charge the vessel’s battery system.

According to Kirby’s modeling, when operating on shore supplied power, the fuel use can be reduced by almost 80%, resulting in an estimated 88-95% reduction in emissions of nitrous oxides, carbon monoxide and hydrocarbons. Engine run time can be reduced between 93 and 98% compared to a conventional inland towing vessel, Kirby said. When in hybrid mode with the generators running, the towboat is expected to have an estimated 27% reduction in emissions compared to a conventional towing vessel, the company added.