Place your chosen image here. The four corners must just cover the arrow tips. For covers, the three pictures should be the same size and in a straight line. Review of Capacity Process Times for Modification Proposal 461 Meeting Monday 5th August 2013 Hayley Burden

2 Background – Capacity Processes  Capacity process runs are instigated by the GNCC via Gemini  Capacity needs to be allocated 4 hours ahead of the end of the Gas Day so there is sufficient time for linked processes to run  NG NTS has analysed the following capacity auction runs;  Day Ahead Daily System Entry Capacity (DADSEC)  Within Day Daily System Entry Capacity (WDDSEC)  Daily Interruptible System Entry Capacity (DISEC)  Day Ahead Daily Network Exit Capacity (DADNEX)  Within Day Daily Network Exit Capacity (WDDNEX)  Daily Off-peak Network Exit Capacity (DONEX)  Assumption that Gemini Housekeeping window will operate an hour earlier in the new Gas Day time

3 Methodology  In each of the identified processes the following occurrences were reviewed (where applicable);  The last occurrence D-1  The first occurrence D  The last occurrence D  Assessment made if the occurrences could:  retain their current time  be moved by an hour  totally removed (or an additional occurrence inserted)  This was then used to populate UNC line by line review spreadsheet

4 Results Overview  Capacity time references associated with the working/business day are unaffected [08:00 and 17:00]  Any 06:00 time reference relating to bids becoming effective could be left as they are. However to align with the new Gas Day they should be replaced with 05:00  End of day capacity auctions runs to be moved forward (e.g. 02:00 time references to be replaced with 01:00)  Keep in view that some capacity processes are linked with day ahead forecasting and any changes there could have a knock on effect

5 UNC Review of Capacity  Section B System Use & Capacity  45 sections containing time references  Analysis of the process has informed our decision and rationale whether a time reference is required to change  Capacity references assigned into categories A-D and whether they require changing. (NB some time references apply to multiple categories)