Exhaust emissions monitoring has become an increasingly important issue as the marine
transportation community seeks to reduce air emissions. However, estimates of current and projected pollution from marine engines are based largely on emissions calculations rather than onboard measurements. These calculations make standard assumptions about vessel operations, engine load profiles, and emissions characteristics in the same way that emissions estimates are calculated for other air pollution sources. While this approach has been proven effective for large-scale inventories of emissions from well-understood sources like factories and cars, these methods may be less accurate when applied to sources that have not been extensively studied. It is widely acknowledged that in-service engines perform differently than the new engines tested and certified by manufacturers. Moreover, individual engines may not perform like the “average engine” described using composite industry profiles or international standards.
The Maritime Administration (MARAD), in support of U.S. fleet technology development and
modernization, has provided support for some of these tests and expects more operators will choose to test their marine engine emissions,. As the principal advocate within Government for U.S. maritime interests, MARAD has initiated a Maritime Energy and Clean Emissions Program. The Program seeks to:
- Investigate and demonstrate the potential for new technologies and fuels to improve marine power plant efficiency and to reduce air emissions.
- Provide guidance and information on maritime energy and emissions regulatory and policy issues.
- Protect the human and natural environment directly in contact with marine activity.
This report provides background discussion and outlines several reasons operators may choose to have their vessels tested. The include improving engine efficiency, meeting regulations, demonstrating environmental stewardship, and contributing to public knowledge and research.
Fundamentals of emissions testing are presented, along with a summary of existing standard protocols.
