Strategies to Reduce Emissions from Harbor Craft
Under the San Pedro Bay Ports Clean Air Action Plan, the following goals are applied for harbor craft that operate at either the Port of Los Angeles or the Port of Long Beach:
- By 2008, all HC home-ported at San Pedro Bay Ports will meet EPA Tier 2 standards for harbor craft or equivalent reductions.
- By 2011, all previously repowered HC home-ported at San Pedro Bay Ports will be retrofitted with the most effective CARB verified NOx and/or PM emissions reduction technologies.
- When Tier 3 engines become available, within five years all HC home-based at San Pedro Bay Ports will be repowered with the new engines.
- All tugs will use shore-power while at their home fleeting location.
Background Information on Harbor Craft Engines
Commercial marine vessel main propulsion and auxiliary engines are classified into categories based upon their size. For example:
- Category 1: 1-5 liters per cylinder displacement
- Category 2: 5-30 liters per cylinder displacement
The majority of the harbor craft engines (engines greater than or equal to 37 kW or 50 hp ) operating in San Pedro Bay Ports fall under Category 1, with the exception of some of the main engines for ocean-going tugs and assist tugboats, which may fall under Category 2.
EPA Emission Standards
United States Environmental Protection Agency (USEPA) emission standards for Category 1 and 2 Harbor Craft engines can be found in Tables 3 and 7 of the Regulatory Update: Overview of EPA’s Emission Standards for Marine Engines.
EPA also publishes a list of engines that have been certified to meet Tier 2 standards.
Progressively more stringent emissions standards are being considered by USEPA for adoption by end of 2007 as follows:
- Tier 3 – proposed to be phased in between 2009 to 2012 depending upon engine size
- Tier 4 – proposed to be applicable to 2014 and later model years
CARB Harbor Craft Regulations
In addition, the California Air Resources Board (CARB) is developing a regulation for Category 1 and 2 harbor craft engines for adoption in October 2007. Starting in 2009, the proposed regulation requires early in-use engine replacement/repower/retrofit to meet USEPA’s most stringent emissions standards applicable. All new harbor craft purchases in California must meet the most stringent USEPA standard applicable at the time of purchase. In addition, the proposed regulation requires installation of non-resettable hour meters and annual recordkeeping/reporting. For more information or to submit comments, refer to the harbor craft section on CARB’s website.
According to the 2005 air emissions inventories of the Port of Long Beach and the Port of Los Angeles, more than 50% of the harbor craft operational at the two ports have Tier 0 engines, contributing more than 50% of total DPM and NOx emissions from all harbor craft. Funding opportunities are available to assist harbor craft owners to replace or repower Tier 0 engines to cleaner engines. Information on funding sources can be found in the grants section of this website.
It is advised that harbor craft owners take advantage of funding opportunities as soon as possible because most of these funds may not be available once CARB’s in-use harbor craft proposed regulation is adopted. Ports staff is available to assist harbor craft companies in identifying and applying for these funds.
Advanced Emissions Control Technologies - Diesel/Electric Hybrid
The two ports are working with Foss Maritime to co-fund development of a diesel/hybrid system for a tug boat.Preliminary work in developing the diesel/electric hybrid system indicates that the hybrid system would use downsized diesel engines from their existing Dolphin class design.The hybrid system would allow the diesel engines to be off during low power demand modes which can account for over 70% of engine run time.In the standard tug design, the main engines would be operating in all modes.The significant amount of engine-off time would reduce fuel use and emissions.In addition, the engines would only be used during the higher load conditions, which is a more efficient operating mode.Emission reductions for this technology are estimated at 44% for nitrogen oxides (NOx) and 44% for particulate matter (PM).Sulfur oxides (SOx) and carbon dioxide (CO2) reductions will also be achieved due to reduced fuel use.Fuel savings of 20 to 30% are expected.