Port of San Diego Deploying Bonnet System to Help Reduce Cargo Vessel Emissions

Clean Air Engineering – Maritime
Clean Air Engineering – Maritime
Clean Air Engineering – Maritime operating a Marine Exhaust Treatment System bonnet at the Port of Los Angeles. Photo: Clean Air Engineering.

Clean Air Engineering – Maritime operating a Marine Exhaust Treatment System bonnet at the Port of Los Angeles. Photo: Clean Air Engineering.

The Port of San Diego revealed in mid-May that it’s moving forward with a system, known as a bonnet, to control and capture cargo vessel emissions. The bonnet will be available for use by cargo vessels that aren’t yet equipped to connect to shore power.

In support of the port’s new Maritime Clean Air Strategy (MCAS), San Diego’s Board of Port Commissioners has approved an agreement with Clean Air Engineering – Maritime Inc. (CAEM) to design, build and operate a barge-based emissions control and capture system, also known as the Marine Exhaust Treatment System (METS).

For vessels that aren’t yet shore-power compatible, METS places a bonnet over the vessel’s stack to capture and treat exhaust while the ship is at berth. Having a bonnet in addition to shore power at the port’s cargo terminals—one at the Tenth Avenue Marine Terminal and one coming soon at the National City Marine Terminal—is expected to help further reduce certain air pollutants like nitrogen oxides and diesel particulate matter.

“The bonnet will give some of our cargo carriers a great option in reducing their air quality impacts while they work to transition their vessels to being shore power compatible,” port board Chairman Dan Malcolm said. “This is another example of how we can maintain and grow our maritime business—and protect jobs—while also improving air quality and quality of life for all who live, work and play on and around San Diego Bay.”

Clean Air Engineering-Maritime President Nick Tonsich added that the port is aggressively pursuing every mitigation measure available.

“We are proud to work with the port and provide our years of experience in this public-private partnership,” he commented.

The bonnet system supports the port’s “Health Equity for All” vision—specifically, the goal to reduce emissions from ocean-going vessels. Additionally, California Air Resources Board (CARB) regulations require that auto carrier vessels reduce emissions while at-berth at California seaports beginning in 2025 by utilizing either shore power or bonnet technology. The port’s National City Marine Terminal primarily processes automobile imports.

According to the port, the total cost of the project is about $11.5 million, with San Diego directing $4.9 million in grant funds received from the California Transportation Commission (CTC). CAEM is covering the rest. The bonnet system is anticipated to be operational by Jan. 1, 2025.

CAEM was founded in 2010 and has experience gained from more than 400 vessel calls and 23,000 hours of vessel-exhaust treatment. It is a full-service company providing both design and build, as well as operations and maintenance of emissions capture and control systems. They have an operational history at the Los Angeles and Long Beach ports.

CAEM is providing up-front capital financing for the portion of the project not covered by the CTC grant and has agreed to the following:

  • Design, build and deliver to the port a METS unit compliant with CARB regulations;
  • Provide the capital necessary for construction, delivery and operation of METS (subject to reimbursement of certain costs through grant funding obtained by the port), and
  • Operate and maintain METS during the duration of the contract through a revenue-sharing arrangement with the port.

The Port of San Diego’s share of revenue is expected to be applied to reduce the capital investment of CAEM over time. CAEM and the port have agreed to jointly own METS until CAEM has fully recovered its investment.

Other notable clean air projects now in the works at the port include doubling shore power for cruise ships in fall 2022 and the installation next year of two all-electric Konecranes Gottwald Generation 6 Mobile Harbor Cranes to replace an obsolete diesel mobile harbor crane at the Tenth Avenue terminal.

The first all-electric tugboat in the U.S., now being built with plans to be operated by Crowley Maritime, is scheduled to operate in San Diego Bay beginning in 2023.

Also next year, 16 new electric trucks and vans are expected to replace gas- or diesel-powered vehicles in the port fleet.