Process for Identifying
Commercially Significant Constraints (CSCs)

1. The ERCOT Engineering Subcommittee (ESC) Steady
State Task Force (SSTF) will complete preparing
the Summer 2001 On Peak base case around December
1, 2000.

2. Using that base case, ERCOT System Planning
will conduct an analysis of the base case
identifying transmission constraints and possible
congestion zones.  The performance criteria used
in evaluating the system will be the ERCOT
Planning Criteria.  These results will be provided
for stakeholder/market entity review and input in
January.

3. Based upon this input, ERCOT will develop a
recommendation and present to the TAC the
identified transmission constraints and related
CSC zones in early February.

4. Once CSC's are identified, shift factors will
be calculated on each transmission constraint
relating to each CSC.  These will be provided to a
stakeholder working group for development of
average shift factors for use in applying
congestion management to the market transactions.

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ERCOT System Planning is preparing calculations
and data to support the identification of
Commercially Significant Constraints (CSC).  This
work will be posted on the Internet very soon for
stakeholder review and input.  A meeting to
discuss these calculations with stakeholders will
be held:

Wednesday, January 31
9:30 AM to 3:30 PM
Red Lion Hotel in Austin (I35 & 290)

The goal of this meeting is to identify which
transmission system contingencies and limiting
elements are commercially significant.  After
CSC's are determined at this meeting, ERCOT will
develop a recommendation and present it to TAC at
their February 7 meeting.

We have also set up an email account to receive
comments.  Its email address is
csccomments@ercot.com  It will be available
throughout this process to receive comments and
input.

Your cooperation in this matter is appreciated.

Kenneth A. Donohoo, PE
Manager of System Planning, Technical Operations
ERCOT
2705 West Lake Dr.
Taylor, TX 76574-2136
(512)248-3003, FAX(512)248-3082