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APPA Weighs in on EPA Proposed Rule to Amend Engine Requirements

The American Public Power Association submitted comments on August 25 in response to the Environmental Protection Agency's proposed National Emission Standards for Hazardous Air Pollutants: Reciprocating Internal Combustion Engines and New Source Performance Standards: Internal Combustion Engines; Electronic Reporting rule.  

APPA’s comments in response to the Proposed Rule addressed arguments by opponents related to the “100-hour provision” in the 2013 RICE NSPS and NESHAP rules, which was vacated in Delaware v. EPA (2015).

The related challenges in that case to the “50-hour provision,” which, pursuant to the agency’s motion, were severed from the Delaware v. EPA case and continue to be held in abeyance pending the agency’s reconsideration of that provision.

The current 50-hour non-emergency provision has been utilized by APPA’s members sparingly to address local reliability concerns such as voltage sags, transmission line maintenance, and non-emergencies such as ramping-up operations of steam generation equipment during black start conditions following an emergency. Also, some of APPA’s members have entered into financial agreements to dispatch the engines under the 50-hour provision.


APPA, in its comments, noted that it has long advocated for EPA to allow limited hours of usage under the RICE rules for electric utilities to call on “emergency engines” on a limited basis to address “non-emergency uses” to stabilize and protect local electricity transmission areas.  In its comments, APPA refers to these RICE as “emergency engines” to distinguish them from RICE at members’ facilities that are compliant with the RICE regulations.

“Many of APPA’s members own such engines, which are not cost-effective to retrofit but are maintained and tested, consistent with the RICE regulations so that they can be operated reliably as emergency engines for brief periods for emergency or non-emergency purposes pursuant to the RICE regulations,” APPA noted.

APPA members also, from time to time, have entered into financial arrangements to dispatch RICE units in non-emergency situations with other generation operators in “balancing areas” and/or with independent system operators and regional transmission organizations.

In past discussions with EPA staff and in briefs in defense of the use of the emergency engines in the Delaware case -- which APPA participated as an Intervenor Respondent on EPA’s behalf- -- APPA emphasized that rural communities, including municipally-owned power plants and rural cooperatives that are literally “at the end of the transmission line,” have been more susceptible to voltage sags and other local electricity outages that jeopardize their local service areas.

APPA Urges Retention of 50-Hour Provisions in RICE Rule

Removal of the 50-hour provisions from the current RICE rule “could harm public power communities because municipally owned and operated power generators will no longer be able to call on these onsite engines to help stabilize and protect the local transmission system or to maintain water pressure to operate fire pumps and safety lighting,” APPA argued.

“To the extent that some of the Association’s members, all of which are not-for-profit entities, enter agreements with balancing authorities or other entities for demand response, the recission of the rules also will eliminate a modest funding source that cities use for maintenance and testing of these emergency engines and fuel for the engines,” it said.

EPA sought comment on whether there are potential revisions that would narrow the 50-hour provision “to ensure that its use is limited to remote rural areas (if those are the only areas where it is needed).”

APPA does not believe the non-emergency provision should be limited to “remote rural areas.”

“Now, and over the next decade, APPA believes that the importance of the 50-hour RICE provisions may grow in both rural and urban areas, given the increase in non-dispatchable generation (e.g., intermittent energy sources like solar and wind-generated power) and load growth,” it said.

In addition, emergency engines are also a viable means for addressing unprecedented weather conditions and other events across the country, APPA said.

Extreme weather events have not been confined to Texas and California and include areas in Kansas served by KPP Energy, it noted.

In 2021 and 2022, the Southwest Power Pool region experienced widespread failure in the natural gas markets. Intermittent generation was not available, and natural gas dispatchable resources were limited due to natural gas availability. “While the events in 2021 and 2022 were short in duration, even the smallest generator was critical to prevent local voltage collapse and cascading outages,” APPA said.

“Public power, like other power systems, address the impending loss of transmission by dropping load, alerting resident to discontinue the use of unnecessary appliances, etc. The ability to operate emergency engines under the 50-hour provision during these events can provide a valuable, if very limited, transition tool to ‘lower generation’ safely or to bring up engines from black start conditions, and thus protect employees and generation resources, the surrounding community, and the environment.”

EPA also asked for comment on whether it should delete the provision rather than attempting to narrow it or make other changes to it.

“Our members are adamant that the regulation should not be deleted. As the power sector transitions to lower and non-emitting generation resources, public power utilities are balancing the system with all available resources, including the potential to operate emergency engines,” APPA said.

The trade group also said that the proposed rule appears to seek responses to the arguments that challengers made in Delaware v. EPA, to the 100-hour demand response provisions in the RICE rules.

These challenges were not specifically adjudicated by the court in the Delaware case because the D.C. Circuit held that the 2013 RICE NESHAP 100-hour provisions for the operation of emergency standby engines for the national grid were arbitrary and capricious.

EPA also requested comments related to criticisms of the 50-hour non-emergency provision made in the Conservation Law Foundation’s brief, which was filed in the Delaware case before CLF’s challenge to the 50-hour provision was severed from the case, and the 50-hour provision was remanded to the EPA for further consideration.

Petitioners and supporting Intervenors-Petitioners argued that demand response in capacity markets based on the use of emergency generators have, had, or will have negative effects on the overall reliability of the national electrical grid for a number of reasons.

APPA argued that retaining the 50-hour non-emergency allowance “did not and will not affect the reliability of the U.S. electric markets, nor did it or will it incentivize operators or ‘energy brokers’ to bundle and attempt to dispatch old engines, forcing out more efficient and/or cleaner generation.”

In APPA’s experience over the last decade, the use of emergency engines under the 50-hour provision has not made the transmission of electricity more vulnerable, it noted.

“The use of emergency engines is not viable to meet the nation’s demand for electricity and has not replaced the energy supply from conventional electric generating units. These emergency engines are not as efficient as regulated RICE, and they are not as economical to operate, even for short time intervals, except for non-emergency and emergency events when there is no other EGU available.”

Nor does the Association “believe that there is any evidence that any local or regional operator has ever suggested the use of these emergency engines is a solution or potential solution to current national energy transmission problems, which are generally attributed to insufficient transmission infrastructure and increased energy demand around the country.”

The majority of the emergency engines that would be allowed to run under the 50-hour provisions were built decades ago and are not nearly as efficient as modern RICE-compliant internal combustion engine generators based on fuel input and energy output, it added.

Electronic Reporting Provisions

The proposed rule also seeks to add electronic reporting provisions to simplify reporting by affected sources and to make the data more readily accessible.

APPA said that provisions for reporting the dispatch of emergency engines need to be clarified to prevent confusion, particularly in the situation where the engine is dispatched by a balancing authority or transmission or dispatch operator.

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