NOTICE DATE:  April 30, 2008

NOTICE TYPE:  W-A043008-01   Settlements

CLASSIFICATION: Public

SHORT DESCRIPTION:  Corrupt data in calculations of price adjustments
for Non-Spinning Reserve Service 

INTENDED AUDIENCE:  QSEs

DAY AFFECTED:  Operating Day April 22, 2008

LONG DESCRIPTION:  ERCOT has discovered that a number of files used to
yield the price adjustments for Non-Spinning Reserve Service for
Operating Day April 22, 2008 (intervals 1645 through 2115) included
corrupt data.  The price adjustments posted April 23, 2008 were related
to Market Clearing Prices for Energy (MCPEs) adjustments required as a
result of the Protocol changes implemented by PRR 650, Balancing Energy
Price Adjustment Due to Non-Spinning Reserve Service Deployment.  In
light of the corrupt data, ERCOT will restore the MCPEs to their
original values, then recalculate and repost the validated price
adjustments once these data files are restored and the underlying data
verified.

The Initial Settlements Statements for April 22, 2008 (intervals 1645
through 2115), will use the originally posted (non-adjusted) Balancing
Energy Service MCPEs for the affected intervals.  After ERCOT validates
the data and recalculates the MCPEs, future Settlements will use the
adjusted prices.

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/> .

yl