---------------------- Forwarded by Caroline Emmert/HOU/ECT on 04/18/2001 04:13 PM ---------------------------


Caroline Emmert
04/18/2001 03:56 PM
To:	kalmeida@caiso.com
cc:	Donna Johnson/PDX/ECT@ECT 
Subject:	Question about Instructed/Uninstructed Energy Data Usage

Keoni,

We are, still, struggling to fully understand the Instructed/Uninstructed Energy data (IE), specifically the two columns that report Uninstructed Deviation and Uninstructed Energy.

The volumetric totals in one of these two columns is supposed to match the volume in the Settlement Detail file for Charge Type 407.  However, I have discovered a couple of (annoying) things in September:

In comparing the two columns within the table - 
For LocationTypes L and C, there is no volumetric difference between the two columns.

For LocationType G, there is a volumetric difference of 153.15 (more in the Deviation column than in the Energy column)

In comparing IE to the Settlement Statement data - 
When I use the volumes in the Uninstructed Energy column for all LocationTypes, I have a volumetric difference of 10.52 (less in the IE data).
However, when I use the Uninst Energy column for L and C, and the Deviation column for G, I then have a volumetric difference of 142.63 (less in the Settlement Statement Detail data).

My question is two- or several-fold:

What causes the volumes in the two columns to be different for the G type?  I could find no discernable value to make it change anywhere in the data.
Which column has the values that the ISO uses in determining the total net position for EPMI?
Why don't the two sets of volumes match (IE to Settlement)?

I really need to understand this, as we are required to tie all of our customer's volumes back to the Settlement Statement file, and, again, when the backup file doesn't match or is inconsistent, that makes our goals that much harder to achieve.

Caroline