Caterpillar Inc. Announces Generator Set Technology Portfolio to Meet Tier 4 Interim Emissions Standards

Peoria, Ill. - Caterpillar Inc. announced today its portfolio of technologies to meet Tier 4 Interim emissions regulations for mobile and stationary generator sets. "Building on a legacy of diesel engine expertise, we are ready to meet the next phase of emissions compliancy," said William J. Rohner, vice president of Caterpillar Electric Power Division.

Diesel Engine Regulations
Beginning January 1, 2011, the U.S. Environmental Protection Agency (EPA) will introduce the next phase of its Tier 4 emissions control regulations, which significantly limit emissions of oxides of nitrogen (NOx), particulate matter (PM), hydrocarbons (HC) and carbon monoxide (CO). These regulations affect the majority of non-road mobile equipment powered by diesel engines greater than 130 bkW, including mobile generator sets. Stationary diesel engines, such as those used in standby and prime power generator sets, are regulated separately, but to similar standards as non-road mobile equipment. However, the challenges facing the electric power industry are unique in a number of areas, particularly above 900 bkW, where the regulations focus on reducing NOx emissions from generator sets by 90 percent, compared to a 45 percent reduction for other equipment types.

Caterpillar Emissions Reduction
"The technology used to meet EPA Tier 4 Interim regulations is not new to Caterpillar," explained Robert Koval, global product director of Caterpillar Electric Power Division. "It is an evolution of existing technologies used by our organization and our dealer partners for decades." Millions of dollars have been invested in the research and development of cleaner engines and integrated emissions reduction techniques. Engineering teams across all of the Cat® product lines have leveraged their expertise to enhance customer value while meeting and exceeding both federal and local regulations. "Cat Tier 4 Interim generator sets will be built on the same principles of performance, reliability and durability as preceding Tier 2 and Tier 3 models," concluded Koval.

Technology Portfolio

To provide Electric Power customers with the most economical and efficient emissions solutions, Caterpillar has developed three different engine-integrated technology packages which can be used, in combination, to address the various emission reduction levels required by the EPA regulations. The technologies have been developed, in conjunction with the wide range of Cat engines, to provide optimal performance while minimizing impact on generator set space requirements and maintenance hours. Customers can expect a 25 - 50 percent price increase on Tier 4 Interim generator set packages.

o 130-560 bkW

Engine Technology: An electronically controlled air management system lowers the combustion temperature by combining a small amount of non-combustible gas with the combustion air, resulting in decreased NOx output.

Aftertreatment: A diesel oxidation catalyst and particulate filter with an automated regeneration system are incorporated into the package design to reduce PM to less than the regulatory requirement.

o 560-900 bkW

Engine Technology: An electronically controlled air management system lowers the combustion temperature by combining a small amount of non-combustible gas with the combustion air, resulting in decreased NOx output. As the regulated PM limit is higher in this power range, the emissions control on the engine alone can meet the requirement without the need for aftertreatment.

o 900 bkW and above

Engine Technology: Low soot combustion techniques, incorporating detail changes to piston bowl design, injector configuration and turbocharger matching.

Aftertreatment: A diesel oxidation catalyst, combined with a selective catalytic reduction (SCR) module, with an air-assisted urea injection system, form the clean air system for larger diesel generator sets. In addition to the Caterpillar-designed aftertreatment system, a dosing control module, diesel emissions fluid (DEF) tank and air source are integrated into the generator package design.

Integrated Systems and Dealer Support

Cat Tier 4 generator sets are capable of integrating into larger power systems that could include UPS, Switchgear and ATS products. To support this new line of generator sets, Cat dealers and technicians will be factory trained in emissions technology installation and service.

For more than 80 years, Caterpillar Inc. has been making progress possible and driving positive and sustainable change on every continent. With 2009 sales and revenues of $32.396 billion, Caterpillar is the world's leading manufacturer of construction and mining equipment, diesel and natural gas engines and industrial gas turbines.

For more information on Cat generator sets and continuous power systems, or to find the Cat dealer nearest you, please visit us on the web at For technical information or to have a dealer contact you, visit

Press Inquiries Dan Matarelli
Tel: 309-578-6614

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