Page 47: of Marine News Magazine (November 2023)

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teries. All of this happens seamlessly through Stewart and ning, the towboat is expected to have an estimated 27%

Stevenson’s power management system.” reduction in emissions compared to a conventional towing

Propulsion is provided by two 575 KW Danfoss elec- vessel, the company added. tric motors that can be driven either by the Corvus Orca Maarten Poort, Shell’s general manager for shipping and

E2250V energy storage system, which provides 1,243 KWH maritime in the Americas, said, “The Green Diamond of power, or, if needed, onboard Caterpillar C18 generators. demonstrates how industry can collaborate to make strides

Norway-based Corvus Energy earlier this year opened towards pro? table decarbonization in the shipping sector. a new factory Bellingham, Wash. in response to a “signi? - It’s concrete action in the right direction—with recogni- cant uptake in opportunities for maritime batteries from tion by those involved that leveraging innovation for low- the U.S. market”. er-carbon outcomes is critically important for our indus- “Inland towboats and tugs are ideal candidates for try, for our companies, for our communities.” electri? cation with batteries because their routes are of- “The plug-in hybrid design offers numerous advantag- ten shorter and closer to shore [where access to charging es for towboats in certain trades,” said Mitch Jones, vice is available],” said Erik Larsen, Corvus Energy VP sales, president of San Jac Marine. “We are already looking at

Americas. “Recent electric vessel projects in the North building follow-on vessels.”

American market include HaiSea Marine’s new battery Asked whether Green Diamond will lead the way for powered escort and harbor tugs for a lique? ed natural gas more plug-in hybrid electric towboats in Kirby’s ? eet, (LNG) export facility in Kitimat, and the Crowley eWolf O’Neil said, “Green Diamond has been an incredible proj- tug currently under construction at Master Boat Builders.” ect of which we are extremely proud. There are operational

While designing and building a ? rst-of-its-kind vessel and environmental bene? ts to the design, and we are ex- such as Green Diamond can be dif? cult, a limited regula- ploring future possibilities across a range of options.” tory guidance for Sub-Chapter M hybrid-electric vessels and how to work that guidance into the design of a vessel pre- sented its own set of challenges, O’Neil said. “Supplier part- nership and collaboration was critical was early and proac- tive engagement with the U.S. Coast Guard and ABS. Given the breadth of ‘new territory,’ all stakeholders in this project took a signi? cantly more involved approach than is typically required with established, conventional vessel types.”

A Shell-owned Zinus charging system will be used for dockside charging of the battery system, allowing the ves- sel to complete trips within the Houston area without us- ing its generators, Kirby said. Shell Energy Solutions will provide electrical power matched 100% by Green-e certi- ? ed renewable energy certi? cates to charge the vessel’s bat- tery system.

“This really puts the ‘green’ in Green Diamond,” O’Neil said. “Operationally, the vessel can and will operate in any and all areas and types of service as a conventional inland towing vessel. It is not restricted if shore charging infra- structure is not available. Even without shore-charging, it will see a greater level of fuel ef? ciency and emissions re- ductions than a conventional vessel.”

According to Kirby’s modeling, when operating on shore supplied power, the fuel use can be reduced by al- most 80%, resulting in an estimated 88-95% reduction in emissions of nitrous oxides, carbon monoxide and hydro- carbons. 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 run- www.marinelink.com MN 47|