M/V Green Diamond, the first plug-in diesel hybrid electric towboat in the U.S. is now in service.
Built by San Jac Marine for Kirby Inland Marine at the company’s shipyard in Channelview, Tx., the new “eco-tug” vessel was constructed with “a focus on efficient operations and reduced maintenance through extended service intervals by leveraging the inherent benefits of a diesel-electric design combined with an energy storage system.”
The 73.6-foot towboat is time chartered by the Shell Trading (US) Company and is in service moving barges in the Port Houston area.
Shell Energy Solutions is providing electrical power to charge the vessel’s Corvus Orca series battery system via a dockside system supplied by Zinus that can be enhanced by adding or removing battery packs based on the towboat’s power needs.
Dockside battery charging will allow the boat to operate on trips within the Houston area without ever needing to start its onboard generators, which can be utilized to charge the vessels batteries. A full charge using shoreside power can be completed in six hours.
Propulsion for the Green Diamond is provided by two 575 kilowatt Danfoss electric motors that can be driven either by the battery system or, if needed, by its dual Caterpillar C18 generators.
Stewart & Stevenson Manufacturing Technologies, another Kirby company, designed and installed the power management, control and propulsion systems.
Capable of shore-charging as well as self-charging if no shore charging infrastructure is available, the towboat’s propulsion system offers fuel savings and emission reductions of up to 80 percent over those reached by a similar-sized standard system and quieter operation compared with a conventionally powered vessel of its class.
The new propulsion system also reduces maintenance down time, and significantly cuts both fuel costs and toxic emissions.
Speaking at Green Diamond ’s christening, Christian O’Neil, president of Kirby Inland Marine, said “We are excited to be the first to market with a plug-in hybrid inland towing vessel. Barge transportation is already the cleanest and greenest way to move a wide variety of cargoes in America, and we are working to make it cleaner and greener. Our customers who are focused on reducing their emissions want more efficient options. This solution is available today.”
Houston-headquartered Kirby Inland Marine operates and manages the nation’s largest fleet of inland tank barges and towing vessels which efficiently and safely transport petrochemicals, refined products, black oil, and agricultural chemicals from producers to intermediaries to end users.