Electric Power Outlook - Pennsylvania Public Utility Commission

Section 3 – Regional Reliability
Regional Reliability Assessments
This section summarizes the regional reliability assessments of NERC, RFC and PJM for
generation and transmission capability.
The reliability of the interconnected bulk power system is defined in terms of two basic and
functional aspects. Adequacy is the ability of the bulk power system to supply the aggregate
electrical demand and energy requirements of the customer at all times, taking into account
scheduled and reasonably expected unscheduled outages of system elements. Operating
Reliability is the ability of the bulk power system to withstand sudden disturbances such as electric
short circuits or unanticipated loss of system elements from credible contingencies. Adequacy can
be expressed in terms of either reserve margin or capacity margin. Reserve margin is the
difference between available resources and net internal demand (total demand less dispatchable,
controllable capacity demand response), expressed as a percentage of net internal demand.
Capacity margin is the difference between available resources and net internal demand, expressed
as a percentage of available resources.
North American Electric Reliability Corporation
The North American Electric Reliability Corporation’s (NERC’s) mission is to ensure the
reliability of the bulk power system in North America. To achieve this objective, NERC develops
and enforces reliability standards; monitors the bulk power system; assesses and reports on future
transmission and generation adequacy; and offers education and certification programs to industry
personnel. NERC is a non-profit, self-regulatory organization that relies on the diverse and
collective expertise of industry participants that comprise its various committees and sub-groups. It
is subject to oversight by governmental authorities in Canada and the United States. NERC
assesses and reports on the reliability and adequacy of the North American bulk power system
according to eight regional areas. The users, owners and operators of the bulk power system within
these areas account for virtually all the electricity supplied in the United States, Canada, and a
portion of Baja California Norte, Mexico.
Reliability Assessment
The 2010 Long-Term Reliability Assessment 59 represents NERC’s independent judgment of the
reliability and adequacy of the bulk power system in North America for the coming 10 years.
NERC’s primary purpose in preparing this assessment is to identify areas of concern regarding
the reliability of the North American bulk power system and to make recommendations for their
remedy.
NERC states that the electric industry has adequate plans to provide reliable electric service
across North America through 2019. Planning reserve margins have increased compared to 2009
projections due mainly to the economic recession, which has reduced demand projections. For
59 NERC, 2010 Long-Term Reliability Assessment, October 2010.
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Pennsylvania Public Utility Commission