John Quinn 100 Constellation Way

Director – Environmental Affairs Suite 1000C

Baltimore, Maryland 21202

410-470-1751

443-213-3204 Fax

3 September, 2010 Via email and post

Robert Wayland, Group Leader

Energy Strategies Group

US EPA

Research Triangle Park, North Carolina 27711

Mail Drop D243-01

Cc: Melanie King

Re: Petition for Reconsideration of National Emission Standards for Hazardous Air 

Pollutants for Reciprocating Internal Combustion Engines, Final Rule

RIN 2060-AP36

EPA Docket No. OAR-2008-0708

Dear Ms. Jackson:

Constellation Energy appreciates the opportunity to express support for EnerNOC’s Petition for 

Reconsideration of National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal 

Combustion Engines, Final Rule, submitted by Beveridge & Diamond, PC, May 27, 2010. We understand 

EPA has granted the petition for reconsideration.

Constellation Energy

Constellation Energy (www.constellation.com) is a leading supplier of energy products and services to 

wholesale and retail electric and natural gas customers. It owns a diversified fleet of generating units 

located in the United States and Canada, totaling approximately 9,000 megawatts of generating capacity, 

and is among the leaders pursuing the development of new nuclear plants in the United States. The 

company delivers electricity and natural gas through the Baltimore Gas and Electric Company (BGE), its 

regulated utility in Central Maryland. A FORTUNE 500 company headquartered in Baltimore, 

Constellation Energy had revenues of $15.6 billion in 2009. 

Petition for Reconsideration – Change 15-hour limit on emergency engines to 60 hours or the 

minimum hours required by the ISO, whichever is less

Constellation Energy supports EnerNOC’s petition for reconsideration of the rule, specifically with respect 

to the 15-hour operating limit on emergency DR. The 15 hour limit for emergency engine operation in the 

regulation currently says, “The 50 hours per year for non-emergency situations cannot be used for peak 
shaving or to generate income for a facility to supply power to an electric grid or otherwise supply power 

as part of a financial arrangement with another entity; except that owners and operators may operate the 

emergency engine for a maximum of 15 hours per year as part of a DR program if the regional 

transmission organization or equivalent balancing authority and transmission operator has determined 

there are emergency conditions that could lead to a potential electrical blackout, such as unusually low 

frequency, equipment overload, capacity or energy deficiency, or unacceptable voltage level.”

Constellation Energy favors EnerNOC’s request that the italicized language above be revised to read, 

"...may operate the emergency engine for a maximum of 60 hours per year or the minimum hours 

required by Independent System Operator tariff, whichever is less..." 

The Rationale behind the request for 60 hours is:

1. ISOs do not have the discretion to dispatch DR resources to take advantage of the greater 

hours. The emergency DR programs are only called under very specific, planned, and controlled 

circumstances. The system operator must report operation in any emergency state to NERC.

NERC requires development of formal plans for Capacity and Energy Emergencies, and precise 

implementation when calling emergency DR events.

2. The 15 hour limit may prevent emergency engines from participating in emergency DR programs. 

The PJM FERC Tariff for the Emergency Load Response program requires a minimum 

availability of 60 hours. PJM’s Reliability Assurance Agreement states that a party must agree to 

reserve for interruption ...at least 10 interruptions per planning period. In addition, a party must 

agree to reserve interruptions of at least 6-hour duration. Hence the 60 hours: 10 interruptions at 

6 hours duration per year.

In summary, Constellation Energy feels a 60-hour or ISO limit is more rational; based on the existing ISO 

system reliability requirements for this equipment.

Respectfully,

John Quinn

Director, Environmental Affairs 

Constellation Energy

Cc: Melanie King King.Melanie@epamail.epa.gov