Review of System Alerts Transmission Workgroup 7th July 2011

Background GBA has been in place for 5 years Time to review current arrangements Builds on discussions had in the SCR workgroups, focused on Gas Deficit Emergency arrangements. Focus is on providing information to the market

What Is a Gas Balancing Alert (GBA)? National Grid have a UNC obligation to notify system users of a potential ‘significant’ end of day (EOD) supply / demand imbalance A GBA may be issued either day ahead or within day Or Aimed at prompting a market response to supply or demand

Day ahead GBA UNC describes the day ahead process as D-1 forecast demand being >= forecast total system supply. The D-1 GBA Trigger Level is based on typical supply levels and forecast demand. Consider: Reviewing name (change from a GBA) Clarifying assessment methodology Introducing the ability for NGG to recall What market response is expected?

Within Day GBA Consider: Market response versus SO action Introducing the ability to for NGG to recall Developing ability to signal a within day issue as well as EOD issue Information requirements From SO From industry Market response versus SO action

Next Steps… Work with the industry to develop proposals July Panel – request a review of the GBA process through the Request procedures National Grid to submit proposal/s in line with the review group conclusions.