1. DN Interruption Reform
Gas Customer Forum
27th July 2009

2. Agenda Background to DN Interruption Reform
Outcome of 2008 DN Interruption tender
DN Analysis
Proposed Approach
Next Steps

3. Background to DN Interruption Reform
Implemented 1 April 2008
DNs tender for interruption rights three years ahead of use
DNs incentivised to procure appropriate level of interruption and investment in networks
Fewer interruptibles from 2011 onwards

4. Outcome of 2008 DN Interruption Tender
Post 2011 Interruptible Load
% peak load
No. of sites
SGN
<1 7
NGN
1.05 5
NGG
0.2
WWU
0.4 4

5. All DNs Prelude

6. All DNs Post Mod 90

7. Approach Identify Firm Load Shedding Capability post Mod 90
Establish a target based on the performance achieved in Exercise Prelude
NEC wants speed and confidence on DN deliverability
Load shed in 4 hours
LDZ specific
Resources available for Site visits where required
Shipper obligations remain to maintain site contact details

8. Example – NGG Analysis Prelude

9. Example – NGG Analysis post Interruption Reform

10. Next Steps Revised DN Safety Case submissions August 2009
DN Best Practice
Preparation
Data Validation [NG top 200 per LDZ]
Site Visits > 2 million therms [NG 212 across 5 LDZs]
NEC involved
Industry Engagement
GATG, Distribution w/stream, Gas Customer Forum
Emergency Exercises (2009 and 2010)
Highlight Target Customers
Recycling Contact Information
Escalating Contact Information
Increased Number of Site Visits
Revised DN Safety Case submissions August 2009