Presented by: Becky Webb, PE, Senior Engineer, ComEd Transmission Planning

1. Becky Webb, PE
Senior Engineer
ComEd Transmission Planning
Planning for the Future:
The Changing World of the
Electric Transmission System
2013 SWE Conference

2. 1
Exelon

3. ComEd Overview
• ComEd and its nearly 6,000 employees are responsible for maintaining more than
70,000 miles of power lines that make up the electric transmission and distribution
systems in northern Illinois.
• ComEd provides customer operations for more than 3.8 million customers across the
region, or 70 percent of the state’s population, which includes the third largest city in the
United States. The service territory covers 11,400 mi2 (29,500 km2) in Northern Illinois.
• ComEd is committed to improving electric service reliability for its customers. Since
2001, ComEd has invested approximately $9 billion to expand, upgrade, and maintain
the reliability of its transmission and delivery systems.
2

4. Objectives
• Understand the role of the transmission planning engineer for the electric
power system
• Highlight recent trends, policies, and regulations that impact the electric
power system
• Identify challenges of planning the transmission system
3

5. Electric Power System
1. Electricity is generated at one of the many different power plants.
2. Electricity travels from the power plant over high-voltage transmission lines to
substation.
3. At a substation, the electricity voltage is lowered so that it can travel over the
distribution system.
4. Transformers reduce the electricity voltage even further to an acceptable level
for the home or business.
5. Service lines carry electricity to the home or business.
4
Source: www.comed.com/education/understanding-energy/Pages/how-the-system-works.aspx

6. Electric Power System
1. Electricity is generated at one of the many different power plants.
2. Electricity travels from the power plant over high-voltage transmission lines to
substation.
3. At a substation, the electricity voltage is lowered so that it can travel over the
distribution system.
4. Transformers reduce the electricity voltage even further to an acceptable level
for the home or business.
5. Service lines carry electricity to the home or business.
5
Source: www.comed.com/education/understanding-energy/Pages/how-the-system-works.aspx
Transmission Planner’s Focus

7. Electric Transmission System
• Regulated by the Federal Energy Regulatory Commission (FERC) and the
North American Electric Reliability Corporation (NERC)
6
Source: NERC, www.nerc.com
• NERC - established as the
Electric Reliability Organization
with oversight by FERC
• Develops and enforces reliability
standards
• Annually assesses seasonal and
long-term reliability
• Monitors the bulk power system
through system awareness
• Certifies industry personnel

8. Regional Transmission Organizations
Source: The ISO/RTO Council, www.isorto.org
• Regional Transmission Organizations (RTO) and Independent System
Operators (ISO) manage the electric grid on a regional basis
• Work with local utility to ensure reliability
7

9. ComEd Transmission System
8 Source: PJM 2012 Regional Transmission Expansion Report, www.pjm.com
8
Lake Michigan

10. The Role of the Transmission Planner
• Transmission Planning is all about evaluating snapshots of the electric
transmission system in time.
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• The Transmission Planner is responsible for
studying the reliability of the transmission
system
• Use computer-based models to
represent the electrical parameters of
the elements on the transmission system
• Analyze different types of contingencies
for
• Near-term (1 to 5 years in future)
• Longer-term (6-10 years or more
in future)
• Determine appropriate reinforcement
projects to enhance system reliability
and security

11. Example Transmission Model
10
Tie Line to
Neighboring
Utility
Transmission
Station
Transmission
Station
Transmission
Station
Tie Line to Neighboring
Utility Transmission Station
Distribution
System
Distribution
System
Distribution
System
Transmission
Station
Transmission
Station
Generating
Station
Generating
Station
Generating
Station
Generating
Station

12. Sample Contingency Analysis
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Tie Line to
Neighboring
Utility
Transmission
Station
Transmission
Station
Transmission
Station
Tie Line to Neighboring
Utility Transmission Station
Distribution
System
Distribution
System
Distribution
System
Transmission
Station
Transmission
Station
Is power flow
acceptable?
Generating
Station
Generating
Station
Generating
Station
Generating
Station

13. Challenges Impacting Transmission Planning
Future
Transmission
System
Uncertainty
Generator
Deactivations
Renewable
Portfolio
Standards
FERC Order
1000
12

14. Generator Deactivations
• Generator deactivations impact power flows on transmission system
May potentially cause reliability issues due to lack of source in particular
locations on transmission system
• Existing generators facing increased risk to economic viability in today’s
market
Changes to environmental regulations largely impact coal- and oil-fired
generators
Increased supply of
Slowed growth in demand for electricity
• Generator required to notify transmission system operator of generator
deactivation
Generator deactivation must be analyzed to ensure system reliability
Reinforcement projects must be identified if reliability issues exist
Transmission projects typically require long lead time to design and
construct
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15. Generator Retirement
• NERC projected approximately 71 GW of fossil-fired generation to retire by
2022
90% of the 71 GW projected to retire by 2017
44GW of fossil-fired generation was confirmed to retire at time of study
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Source: 2012 NERC Summer Long-Term Reliability Assessment, www.nerc.com

16. Generator Retirement
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Source: PJM Generator Deactivations, www.pjm.com, posted October 4, 2013
• Within PJM’s footprint:
Approximately 7.5 GW of capacity has retired since 2012
1.37 GW of capacity retired in the ComEd footprint in 2012
An additional 12.7 GW will be deactivated by the end of 2015
Approximately 90% of future capacity deactivations required upgrades

17. Challenges Impacting Transmission Planning
Future
Transmission
System
Uncertainty
Generator
Deactivations
Renewable
Portfolio
Standards
FERC Order
1000
16

18. Renewable Resources
• Renewable Portfolio Standards (RPS) – regulatory mandate to
increase production of energy from renewable sources
Typically states mandate a certain percentage of electricity generated from a
particular technology (wind, solar, biomass)
States can choose to apply the RPS requirements to all utilities or only
investor-owned utilities
• Approximately 29 states have implemented Renewable Portfolio
Standard (RPS) requirements to drive the development of renewable
energy and focus on greenhouse gas emission regulation
• Impacts to transmission system include
Location and siting of renewable projects
Changes in power flow due to variability of large-scale renewable generation
• Status of renewable energy production tax credit may threaten
economic viability of potential renewable projects
17
National Renewable Energy Laboratory (NREL)

19. Renewable Resources
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Source: Database of State Incentives for Renewables and Efficiency: http://www.dsireusa.org
Renewable Portfolio Standard Policies..
www.dsireusa.org / March 2013.
29 states,+
Washington DC and 2
territories,have
Renewable Portfolio
Standards
(8 states and 2 territories have
renewable portfolio goals).

20. Challenges Impacting Transmission Planning
Future
Transmission
System
Uncertainty
Generator
Deactivations
Renewable
Portfolio
Standards
FERC Order
1000
19

21. Federal Energy Regulatory Commission (FERC)
Order 1000
• FERC issued Order 1000 in 2011 to support investment in
transmission to account for policy changes and introduction of new
regulations
Requires transmission providers to improve coordination between
neighboring transmission planning regions – participate in a regional
transmission planning process
Requires public utility transmission provider to consider public policy
requirements in planning process
Promotes competition in regional transmission planning
processes
o Removes incumbent utility’s right of first refusal (ROFR) for specific
new transmission facilities selected as part of a regional
transmission plan
o May require changes to transmission planning processes to prepare
for open process
Devise cost allocation principles to recover cost of regional
transmission projects
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The Federal Energy Regulatory Commission (FERC) website, www.ferc.gov

22. Conclusion
• Uncertainties exist when planning for the
future
• Increased challenges in considering new
policies and economic climate
• Transmission organizations changing
traditional planning processes to account
for new challenges
• Transmission Planners tasked to identify
necessary transmission projects to invest
in the reliability of the system
• Increased focus on transmission yields
exciting opportunities for transmission
planning engineers!
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23. Questions?
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• Please feel free to contact me at:
Becky.Webb@ComEd.com