Backup generators used in a broad range of industries, including medical, agriculture, and oil and gas production facilities, are now subject to new emission standards. New EPA regulations for reciprocating internal combustion engines (RICE) went into effect April 1, 2013 (78 Fed. Reg. 6,674). The EPA estimates that there are more than 1 million of such engines in use in the United States.
The new rule finalized by the EPA on January 30, 2013 allows certain existing RICE used as emergency engines to operate up to 100 hours per year without requiring compliance with emission control requirements under certain circumstances. The 100-hour exemption applies if the use is undertaken as part of an emergency demand response program, which incentivizes the limited use of emergency engines during periods of emergency and power grid instability. Such programs are intended to protect the reliability and stability of the national electric service grid and prevent blackouts.
A 2010 rule had limited the operation of RICE in such circumstances to just 15 hours. Despite the increased hours under the new rule, the total combined hours of generator operation to address emergency demand response or local system reliability issues together with the total time spent for maintenance and testing may not exceed 100 hours.
A second component of the new rule prohibits the use of RICE for beneficial peak shaving programs after May 3, 2014. Until this date, only 50 of the 100 hours allowed under the exemption may be used for participation in such programs. Beneficial peak shaving programs have been used by power companies to incentivize lower energy consumption during peak usage hours where grid reliability issues are not of immediate concern.
Engines that exceed the new limits to the exemption will be subject to all emission control requirements for non-emergency generators.
This rule is now in effect; however, on April 1, 2013, four petitions were filed challenging the new rule. Opponents to the 100-hour exemption for emergency demand response programs allege that the new rule encourages air pollution during periods of peak usage when ozone levels are already high. Representatives of the power industry allege that the elimination of the exemption for beneficial peak shaving programs is unwarranted because the limited hours of the exemption would not adversely affect human health or the environment. Given the challenges from both sides, owners and operators of existing emergency generators may want to continue to follow developments related to this new rule as these cases progress.
EPA Technology Transfer Network Air Toxics Web site on this topic is available here: http://www.epa.gov/ttnatw01/rice/ricepg.html
Delaware Department of Natural Resources and Environmental Control v. EPA, Docket No. 13-1093
National Rural Electric Cooperative Ass'n v. EPA, No. 13-1095
First Energy Solutions Corp. v. EPA, No. 13-1102
Conservation Law Foundation v. EPA, No. 13-1104