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Are you ready for EPA’s transition from T4i to T4 final?

Cody Albertus

On January 1, 2015 the EPA emissions regulations for stationary non-emergency power generators are changing from Tier 4 Interim to Tier 4 Final.  Typical applications required to meet these regulations are data center generators operated for storm avoidance or utility stabilization for greater than 100 hours per year, generator sets used for rate curtailment or peak shaving, and locations that use the generator set as their primary source of power.

From a regulation standpoint, the biggest change is the technical limitations for harmful pollutants.  Specifically, the maximum g/kW-hr allowed for non-methane hydrocarbons (NMHC) and particulate matter (PM) will be reduced:





Tier 4i



Tier 4F







This level of reduction to the allowable harmful pollutants has a direct impact on design of the aftertreatment systems and requires additional aftertreatment hardware (exhaust heaters, diesel particulate filters, etc.) which increase initial costs, the size of the generator set, and maintenance costs.  It’s critical to work with an experienced supplier who has a depth of knowledge about emissions reduction processes.

Given that the process of quoting, designing and building a facility may take two years or more, we need to be thinking about the EPA’s future requirements now.

In anticipation of EPA’s 2015 regulations, Cummins Power Generation has taken the lead in emissions reduction technology. We recently introduced a complete range of generator sets, 680-2750 kW, that are Tier 4i Certified and Tier 4 Final ready today! To tap into Cummins’ experience with emissions-reduction technology, contact your local Cummins distributor.