Kirby Inland Marine, LP christened the GREEN DIAMOND, the US’s first plug-in hybrid electric inland towing vessel, at a ceremony in Houston on Friday, August 25, 2023, according to the company's release.
Following the ceremony, the vessel will be time chartered by Shell Trading (US) Company, which will use the boat to push barges throughout the Houston port region. Shell Energy Solutions is providing electrical power matched 100% by Green-e® certified renewable energy certificates to charge the vessel’s battery system. Kirby Inland Marine is a subsidiary of Houston based Kirby Corporation.
The GREEN DIAMOND is the product of collaboration among many Kirby-owned companies. The vessel was constructed by San Jac Marine, LLC, Kirby’s shipyard in Channelview, TX. Stewart & Stevenson Manufacturing Technologies, another Kirby company, designed and installed the power management, control and propulsion systems. A host of vendors provided other key systems for the first-of-its-kind vessel.
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 New Energies US-owned charging system purchased from Zinus will be used for dockside charging of the battery system, allowing the vessel to operate on trips within the Houston area without ever needing to start the generators. 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. When in hybrid mode with the generators running, the boat is expected to have an estimated 27% reduction in emissions compared to a conventional towing vessel.
Kirby Corporation, based in Houston, Texas, is the largest domestic tank barge operator in the US, transporting bulk liquid products throughout the Mississippi River System, on the Gulf Intracoastal Waterway, and coastwise along all three United States coasts. Kirby transports petrochemicals, black oil, refined petroleum products and agricultural chemicals by tank barge. In addition, Kirby participates in the transportation of dry-bulk commodities in United States coastwise trade.