Pricing Manifest Error

Affected Period

Status
Closed

Category
Balancing

Run Type
Imbalance Pricing

Created
28/08/2019 17:19

Last Updated
06/02/2025 09:00

Update 13/09/2019

Further to the below communication, SEMO have identified a manifest error in the calculation of the Imbalance Settlement Price. The following periods have been impacted:

Date	Imbalance Settlement Periods
7^th September 2019	08:30 to 09:00 09:30 to 10:00 13:30 to 14:30 16:00 to 16:30 17:00 to 17:30 18:30 to 20:00
10^th September 2019	08:30 to 09:30
12^th September 2019	08:00 to 08:30

A resolution for this issue (6105) may be tracked via the Known Issues Report, published weekly on the SEMO website.

Kind Regards,
SEMO Trading Operations

Original Message

Dear Market Participants,

SEMO have identified that a manifest error has occurred on the 24th, 26th and 27th of August.

Details of the manifest error is as follows:

A small subset of units have a unique reserve curve whereby they have both a positive slope at the beginning of the curve and a negative slope at the end of the curve. If reserve is binding all units with a non-zero slope should be flagged. The positive slope is not being flagged correctly. This defect is only present on four units. If the unit is on a positive slope and the constraint is binding the unit will not be flagged and may contribute to the price as a result.

SEMO will observe occurrences of this manifest error in the future and amend as part of the repricing project.

Kind regards,

SEMO Trading Operations