NOTICE DATE:  June 9, 2008

NOTICE TYPE:  M-A060608-02   PRR

CLASSIFICATION: Public

SHORT DESCRIPTION:  Implementation of PRR764, Zonal Congestion and
CSCs/CREs

INTENDED AUDIENCE:  QSE Settlement and Operations personnel

DAY AFFECTED:  Operating Day June 9, 2008

LONG DESCRIPTION:  Effective 0800 CPT Monday, June 9, 2008 ERCOT has
implemented congestion-management operations under Protocol Revision
Request 764, "Zonal Congestion and CSCs/CREs." This revision was
approved by the Electric Reliability Council of Texas (ERCOT) Board on
Friday June 06, 2008.  Other aspects of PRR764, such as the reevaluation
of CREs, remain to be implemented.

The operations revision specified by PRR764 requires that CSCs/CREs will
be managed using zonal congestion management guidelines.  Specifically
Zonal Balancing Energy can be deployed only for Congestion Management
purposes to resolve flow limit violations on CSCs and CREs where the
base case or post-contingency limiting element is the CSC or CRE, unless
an Emergency Condition is declared by ERCOT. 

In addition, ERCOT Operations will determine CSC Limits as follows:

(1)               Determine the pre-contingency flow limit on the
directional CSC that results in the CSC or any directional CRE
corresponding to the CSC becoming the base case limiting element, for
all Congestion Zone-to-Congestion Zone transfer studies.

(2)               Determine the pre-contingency flow limit on the
directional CSC to withstand any single contingency that results in any
directional CRE, including elements comprising the CSC, corresponding to
the CSC to become the post-contingency limiting element for all
Congestion Zone-to-Congestion Zone transfer studies.

(3)               The lower of the CSC flow limits from (1) and (2)
above sets the CSC Limit

 

The day ahead advisory limits will be posted on the ERCOT website at
https://tcr.ercot.com/default.cfm?func=tcrpostings
<https://tcr.ercot.com/default.cfm?func=tcrpostings>  .

 

Real-Time the limits will be posted
http://mospublic.ercot.com/ercot/jsp/csc_cre.jsp
<http://mospublic.ercot.com/ercot/jsp/csc_cre.jsp>  each hour. 

 

ADDITIONAL INFORMATION:  The revision modifies protocols and specifies
the use of zonal congestion for CSC/CREs, allowing the grid operator to
resolve a particular type of transmission congestion with
local-congestion management techniques, rather than the zonal-congestion
management used currently. .

The protocol revision specifies the use of CSC's and CREs for the
contingency element/limiting element pair in establishing the CSC
limits. ERCOT will use Zonal Balancing Energy to solve these congestions
issues and will use local congestion to solve all non- CSC/CRE related
congestion.

 

Under local-congestion management, the grid operator is able to deploy
"out-of-merit" generation, as opposed to "merit order" which is based on
bids stacked from least to most expensive.

The details of PRR764 may be found on the ERCOT website at:

http://www.ercot.com/mktrules/issues/prr/750-774/764/
<http://www.ercot.com/mktrules/issues/prr/750-774/764/> 

CONTACT:  If you have any questions, please contact your ERCOT Account
Manager. You may also call the general ERCOT Client Services phone
number at (512) 248-3900 or contact ERCOT Client Services via e-mail at
[log in to unmask] <mailto:[log in to unmask]> .

If you are receiving e-mail from an ERCOT distribution list that you no
longer wish to receive, please follow this link in order to unsubscribe
from this list: http://lists.ercot.com <http://lists.ercot.com/> .

 

dls