On August 9th, Crowley and the Port of San Diego broke ground on the shoreside charging station designed to provide clean energy for the company’s new zero-emissions tugboat, eWolf.

Rendering of the Crowley electric tug eWolf

At the same time, a new California air quality rule for harbor craft will force the tug and barge industry to consider expensive upgrades including to battery-power, according to the American Waterways Operators (AWO). AWO officials told AJOT they were concerned about the impact of the California rule on 68 vessels but requested that AJOT contact naval architectural firm Glosten for comment and analysis.

As a result, on August 14th, Maggie Moon, Chief Marketing Officer, Glosten told AJOT: “As I mentioned to Peter Schrappen (Vice President, Pacific Coast region, American Waterways Operators) when we spoke the other day, as consulting engineers, we walk a fine line in our communications around the industry’s push to decarbonize and the impact that has on vessel operators. I don’t need to tell you all that the CARB Harbor Craft Rule is a hot topic as of late. That being said, we’re happy to provide our take on the matter, but any “on the record” conversations will have to be conducted in writing. If there are certain questions you [AJOT] have for us, please send them over and we can start drafting responses.”

Subsequently, Glosten provided the following responses to questions that AJOT submitted: “Each of the 68 vessels is unique and will face their own challenges in meeting the CARB Commercial Harbor Craft (CHC) emission requirements. Generally, the easiest path to compliance is to install EPA Tier 4 engines with a diesel particulate filter in the exhaust system piping, assuming they are commercially available. Other options include converting to all-electric or using alternative fuels to reduce emissions below standards; but these will likely be much harder to implement for most vessels and will require significant changes to existing designs.”

California Provides Funding Sources For Repowering Harbor Vessels

The response to one question submitted to Moon noted that the California Air Resources Board has proposed several funding sources to help harbor craft repower with lower emission engines. The programs apply to funding opportunities specific to CHC rules. They impact ferries, tugboats, and towboats and include the following:

  • Clean Transportation Incentives: Advanced Technology Demonstration and Pilot Projects
  • Passenger Ferry Grant Program
  • Electric or Low-Emitting Ferry Program
  • Ferry Service for Rural Communities
  • Volkswagen Environmental Mitigation Trust
  • Carl Moyer Program and Community Air Protection Incentives — Marine Vessel Projects

The explanation was that “As far as a viable path forward for the 68 vessels, there are funding programs in place, but apart from that, we don’t have enough insight into CARB’s rule making process to determine if they have a broader strategy to help California operators bring existing assets into compliance.”

Crowley Invests In Battery-Powered Tug & Charging Station

When Crowley and the Port of San Diego broke ground on the charging station designed for the zero-emissions tugboat, eWolf, Matt Jackson, Crowley Vice President of advanced energy, explained: “Building a sustainable, zero-emission port of the future requires pioneering new and innovative technology, as well as a commitment to partnerships so we can meet the needs of our communities, customers and people.”

In a press release, Crowley said the “charging station is a microgrid charging facility that will allow vessels to recharge quickly while reducing peak loads on the community energy grid. It is equipped with two containerized energy storage systems provided by Corvus Energy, a leading supplier of reliable energy solutions in the maritime sector.”

On its website, Crowley says the new battery-powered tugboat, which will soon be operating at the Port of San Diego, demonstrates how “Crowley Maritime Corporation will lead the next generation of industry sustainability by building and operating eWolf, the first all-electric powered harbor tugboat that can complete a job without expending a drop of fuel.”

Tugboat Features

Crowley Chairman and CEO Tom Crowley noted: “The eWolf represents everything Crowley stands for: innovation, sustainability and performance. With this groundbreaking tug design, our team continues to embrace our role as leaders in the maritime industry.”

The company says the new tugboat will substantially reduce emissions compared to diesel powered vessels: “The 82-foot vessel with 70 tons of bollard pull advances Crowley and the maritime industry’s efforts toward sustainability and decarbonization. Over the first 10 years of its use, the operation of the new eTug will reduce 178 tons of nitrogen oxide (NOx), 2.5 tons of diesel particulate matter, and 3,100 metric tons of carbon dioxide (CO2) versus a conventional tug. The electric tug will replace one that consumes more than 30,000 gallons of diesel per year.”

Moon was asked by AJOT whether battery-powered tugs such as the Crowley e-Wolf provide a long-term solution for AWO vessel operators: “Fully electric, zero-emission harbor tugs would, of course, meet or exceed the requirements of the CARB CHC rule. Such tugs do, however, have operational limitations in comparison to mechanical diesel tugs. Depending on what means, and methods are used to overcome those limitations – i.e., to extend operating endurance – the vessel may still have to install exhaust gas treatment equipment to comply with the CARB CHC rule. This would be the same type of equipment that would have to be installed on larger tugs – namely, selective catalytic reduction (SCR) or exhaust gas recirculation (EGR) systems and diesel particulate filters – but likely on a smaller scale.”

However, a Corvus Energy source says that longer range operations for tugboats could be addressed by deploying zero emission hydrogen fuel cell systems that will soon become available. On its website, Corvus explains: “In contrast to battery systems, hydrogen has higher energy density and faster bunkering/charging time. These features make fuel cells more suitable for applications with longer transits and more time in-between each charging point. In combination with batteries or other types of engines, fuel cells can improve efficiency, add fuel flexibility, and extend operation range.”

Challenges For Existing Harbor Vessel Operators

Nevertheless, Glosten sees major costs and challenges for vessel operators meeting the new California rule: “In fact, with the exception of a few classes of sister vessels operating in the Bay Area and LA/Long Beach, they run the gamut, from small construction support tugs to coastwise line-haul tugs capable of trans-oceanic tows. For some, retrofitting with diesel particulate filters may be practically impossible due to basic elements of the design that cannot be changed, like length, beam, and depth. For others, it may be possible to install the required equipment with only limited modifications. Most will fall somewhere in between; but regardless, the nature of the modifications will vary greatly on a case-by case basis. This means that the cost will also vary on a case-by case basis. Given the diversity of the California fleet, it is questionable whether the conversion cost of one or two “representative” vessels can be extrapolated to provide a reasonably accurate estimate of the total cost to bring all 68 vessels into compliance.”