Nuclear generation constitutes the majority of our generating capacity and is the main driver behind Exelon’s low-emission rates. Other factors contributing to our low-emission rates include:
- Non-emitting Conowingo Hydroelectric power plant
- New and existing advanced pollution controls at many of our fossil power plants
- Uprate and efficiency programs that provide additional generating capacity at Exelon’s nuclear and hydroelectric power plants
- Industry-leading capacity factors at Exelon’s nuclear plants
- Continued development of new wind power projects through Exelon Wind and the integration of Constellation’s wind and solar projects into the Exelon Generation portfolio
- Retirement of older less efficient fossil plants
Air Pollution Control Regulations
- In August 2011, EPA issued its final Cross State Air Pollution Rule (CSAPR) to reduce NOx and SO2 emissions in the eastern United States. While the regulation requires complinance effective January 1, 2012, compliance requirements have been stayed by a federal Court, pending resolution of litigation. Exelon has intervened in the CSAPR litigation in support of EPA. The Clean Air Interstate Rule (CAIR) remains in effect in the interim.
Air Pollution Control Regulations
- In December 2011, U.S. EPA finalized its Mercury and Air Toxics (MATS) regulation that is designed to dramatically reduce hazardous air pollutant (HAP) emissions from coal- and oil-fired electric generating units. Exelon supports the final MATS rule due to the enhanced public health and environmental benefits it provides, as well as the regulatory certainty it provides to our industry from a capital planning perspective.
Air Pollution Control Regulations
- Additional 2012 U.S. EPA proposed air rulemakings of interest to Exelon and our industry, include the Agency’s proposed GHG New Source Performance Standard (NSPS) for new baseload and intermediate fossil generating units; consideration of lower particulate matter National Ambient Air Quality Standards (NAAQS); and potential future revisions to the CSAPR program to support future year attainment of ozone and PM NAAQS.
Air Pollution Control Regulations
- See Exelon’s 2011 Form 10-K for more extensive discussion of air regulatory issues facing Exelon, environmental disclosures, and management discussion of environmental risk factors.
Air Pollution Control Regulation
- Copies of Exelon comments filed on U.S. EPA proposed rulemakings, and discussion of Exelon’s policy positions on key issues, can be found in the Policy Positions section of Exelon’s corporate website.
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Managing Carbon Dioxide (CO2) Emissions
The direct CO2 emissions from fossil-fuel electric power generation represented more than 90% of the Exelon Corporation and Constellation Energy total direct GHG emissions in 2011.
In 2011, Exelon Generation’s CO2 emissions declined primarily due to the retirement of the coal-fired Eddystone Unit 1 and retirement of the Cromby plant. Reduced emissions due to these retirements more than offset increased CO2 emissions resulting from the addition to the Exelon Generation portfolio of the Wolf Hollow Plant that was acquired in August 2011. At Constellation, increased CO2 emissions in 2011 were driven primarily by the acquisition of more than 2,600 megawatts of natural gas-fired generation in early 2011. Similar to the case with Wolf Hollow, CO2 emission rates associated with this new generation are approximately 50 percent lower than those of coal-fired plants.
Both Exelon and Constellation portfolio CO2 emission rates were well below the industry average emission rate in 2010 and on a pro forma basis the combined companies’ emission rates remain industry leading. Additional details on CO2 emissions and emissions of other GHGs can be found under Climate Change and in the Exelon Corporation 2011 Sustainability Report.
Managing Nitrogen Oxide (NOx) Emissions
Exelon and Constellation owned-generation portfolio emission rates remained well below industry averages in 2011. Decreased NOx emissions at Exelon Generation were driven primarily by fossil plant retirement. Increased NOx emissions at Constellation were driven, in part, by the acquisition of 2,600 megawatts of natural-gas fired generation in early 2011.
Looking forward, portfolio NOx emission rates will be further lowered under Exelon’s Sustainable Growth Strategy as additional low, or zero, emission generation is added to the portfolio. In addition, post-merger, Exelon now owns 31.32% of the Conemaugh station that is currently installing a selective catalytic reduction system to support reduction of mercury emissions; this system will result in significant co-benefit NOx reductions. Additional information on Exelon’s evolving Sustainable Growth Strategy and actions to reduce emissions can be found in the Exelon Corporation 2011 Sustainability Report.
Managing Sulfur Dioxide (SO2) Emissions
All coal-fired units in which Exelon has an ownership interest utilize scrubbers for SO2 removal. In addition to removing SO2, these systems also achieve co-benefit reductions in acid gas emissions.
Exelon and Constellation owned-generation portfolio SO2 emission rates were well below industry averages in 2011. Reduced SO2 emissions at Exelon between 2009 and 2011 were driven primarily by new SO2 scrubbers that went online at the co-owned Keystone plant in late 2009 (Exelon’s share of scrubber capital cost was in excess of $140 million), as well as to the retirement of several Eisenhower era fossil generating units in 2011. At Constellation, reduced SO2 emissions between 2009 and 2011 were also driven by their co-owned share of the Keystone scrubber project, as well as due to the installation of SO2 scrubbers at Constellation’s Baltimore-area coal-fired plants that went operational in early 2010. Additional information on Exelon’s evolving Sustainable Growth Strategy and actions to reduce emissions can be found in the Exelon Corporation 2011 Sustainability Report.
Toxics Release Inventory (TRI) Emissions
Exelon and Constellation Toxics Release Inventory (TRI) reporting includes data from owned and co-owned fossil generating units such as Keystone and Conemaugh. Overall, TRI emissions at both companies declined significantly in 2010 versus 2009 due primarily to the operation of new SO2 scrubber systems at the joint-owned Keystone Plant (of which Exelon and Constellation are both co-owners), as well as due to the commencement of operation of additional SO2 scrubbers at Constellation’s Baltimore area coal plants in 2010. SO2 scrubbers achieve co-benefit reductions in a number of TRI pollutants, including acid gases and mercury. Both acid gases and mercury reductions will be required under the EPA’s Mercury and Air Toxics Rule (MATS) that is scheduled to require compliance in early 2015 and Exelon’s generation portfolio is well-positioned for compliance due to its investments in pollution control technologies such as SO2 scrubbers.
In the case of Exelon, TRI emissions declined by 44% between 2009 and 2010 and at Constellation TRI emissions declined by 79% for the same time period. TRI data for 2011 will be reported to EPA in July 2012. Additional reductions in TRI emissions are expected due to the retirement of several Exelon Power Eisenhower-era fossil generating units that occurred in 2011. For further information on TRI emissions, please visit EPA’s Web site: www.epa.gov/tri. For a complete listing of all TRI compounds, please see the Exelon Corporation 2011 Sustainability Report.
Compliance Performance
Air Notices of Violation
Exelon’s Environmental Policy requires us to operate in full compliance with all applicable legal requirements and we hold ourselves and those working on our behalf accountable for this commitment.
To assist in maintaining strong environmental performance, both Exelon and Constellation utilize formal Environmental Management Systems (EMS) designed to conform to ISO 14001:2004. Constellation’s EMS program is in the process of being integrated into the Exelon system. As shown in the summary NOV chart on our Results page, Exelon received no air Notices of Violation (NOVs) in 2011, while Constellation received two air-related NOVs.