System information provision

Information What additional information transparency would help us to: Understand what system flexibility is Understand how it is being used now Predict future requirements Help define any possible services / incentives / products etc The aim is to ensure that the system and services required by customers are available when required.

Potential drivers for future changes in system usage LCPD leading to reduction in coal generation Expected increases in wind powered generation Change in storage services Evolving DNO offtake flexibility requirements Evolving Entry flow characteristics

Gas & electricity interaction Increased volatility driven by weather and operational characteristic of new generation plant: High wind load factors could result in little CCGT use large amounts of wind generation Low wind load factors could result in a sudden and large swings in gas demand Combination of extra cold weather and additional CCGT demand Could result in significant change in gas demand within-day Could see CCGTs operating with lower load factors but greater / shorter notice frequency Demand volatility (particularly within day) requires flexibility in: Supplies, Demands, and Networks

Potential developments for October 2009 Areas to consider: Service Definition – What is Flexibility (if not definition used under 195AV) ? Demand volatility within day Change in linepack across the day? Delta change in demand/linepack during the day (high point vs low point) Flows vs forecast Any other views?

Potential Information for October 2009 Possible areas: General level of flow change – eg 1/24th vs actual hourly flows (National, zonal, by exit /entry point type) Predictability – Outturn versus earlier notification/forecast Impact on Linepack Already obligated by 0195v to publish hourly linepack data on zonal level from 2010. Bring this forward to 2009? Open to users views on what would help them understand the situation better

Graphs Following graphs show typical changes on the system on a typical day and may help identify the type of information users would find helpful.

Example of current Demand flow rates

Example of current flows by Offtake types

Predictability – Total CCGT OPNs vs actual

Linepack variation within day (195AV data at National Level)

Summary The Graphs show potential for deriving indicators of change in flow variation / predictability based on existing data Over time these indicators would give signals on whether flows were becoming more volatile and/or less predictable. Would potentially provide better clarity on the types of products/services that customers want going forward What information would the industry find valuable in making their own assessment of future flexibility requirements ? Do users see value in holding a specific workshop(s) to identify user requirements in this area ?