190 likes | 353 Views
Demand Side Investment Planning. Transmission Planning Code Workshop 2 1 st May 2008. Introduction. Supply assumptions for planning were discussed in Workshop 1 (3 rd April)
E N D
Demand Side Investment Planning Transmission Planning Code Workshop 2 1st May 2008
Introduction • Supply assumptions for planning were discussed in Workshop 1 (3rd April) • Aim of this presentation to describe how demand forecasts and Offtake Capacity Statement (OCS) information are used for investment planning
Basis for Investment Planning • Gas Act 1986 (as Amended by the Gas Act 1995) • Economic and efficient • Standard Special Condition A9. Pipe-Line system Security Standards • Firm demand is likely to be exceeded (whether on one or more days) only in 1 year out of 20 years. • Special Condition C2 Long Term Development Statement • Identify likely developments over a 10-year period • Special Condition C8E. NTS gas exit incentives, costs and revenues • Respond to requests for incremental capacity • Gas Safety (Management) Regulations 1996 (GS(M)R). • Deliver appropriate pressure at offtake
Provided by Customers Contracted quantities Direct connects Offtake Capacity Statements From DNs Firm commitment for 4-years (to 2011/12) Indicative for 1- year (2012/13) Section H - OAD Indicative load duration information from DNs Pressures ANOPs for direct connects Within OCS for DNs Provided by National Grid Internal forecasts At least 10-years Annuals, Peaks, Load duration curves Sectoral analysis Econometric modelling Demand Information
Demand Forecasting Methodology • Describes National Grid’s approach to developing demand forecasts • Peak Day forecasts • Load Duration Curves e.g. 1 in 50 (severe), average • Published on National Grid’s website
Gas Demand Forecast • 2007 saw another fall in DN demand • Higher prices • Energy efficiency • Demand destruction • 2008 Forecasts significantly lower • Continued high prices • Loss of demand in large firm / interruptible sectors in early part of forecast • Demand slightly higher in early part of 2008 • Uskmouth Power station – LDZ connection
Offtake Capacity Statement data • OCS process runs in parallel to TBE process • Initiated 1 June each year • OCS agreed by 30 September for the approaching gas year (Y) to year Y+3 • DNs may revise bookings in future years • UNC TPD Section B: Offtake Capacity Statement process • Signals DN 1 in 20 peak day requirements for Offtake Capacity and Agreed Operating Pressures • UNC OAD Section H: Long term demand forecast data • DN off-peak forecast data • Used to inform TBE demand forecasts • Split of offtake flows used as input to network analysis for off-peak analysis
Timeline for Investment Planning - Exit confirmation of annual Plan Exit analysis Dec investment proposals published in TYS May-June initial TBE Base Case available June-July OCS requests and DN offtake forecasts Aug-Sept Analysis of requests and discussions with DNOs end Sept DNOs notified of Offtake Capacity holdings and AOPs
Transporting Britain’s Energy (TBE) process • Annual consultation process with industry • Consensus on likely supply and demand patterns over the ten year planning horizon • Conclusions published in Ten Year Statement each December • Base Case scenario • Range of potential supplies • Range of potential demands
Interaction between OCS and NG Forecasts • OCS info limited to 5-years • But requirement is for a 10-year plan • For the first 5-years • OCS provides the definitive measure of DN 1 in 20 requirements • NG forecasts analysed as a sensitivity • For the last 5-years • NG forecast is the only source of information
Demand Scenarios – Balancing Assumptions • Investment planning analysis must start from a balanced supply/demand position for any demand day being studied • If available supply exceeds total demand • Supplies are reduced using balancing/rank/range assumptions • If total demand exceeds available supply • After taking into account potential new supplies • Power station load is reduced • Where OCS data is used, DN loads will be reduced for Plan Years 5+ before power station load is reduced* • Exceptions are power station loads at extremities of network *This corresponds to the indicative (5th) year onwards in the OCS
Hierarchy of analysis • Flat (10-year horizon) NG forecast • Flat (OCS) • Flex (OCS) • Pressure (OCS) • Off peak analysis (10-year horizon)
Flat Capacity Uncertainties • Demand patterns are generally better understood than potential supply patterns • Population centres and CCGT demands and locations are reasonably stable • Supply distribution has a major impact on ability to deliver demand side requirements • Sensitivities • What if Grain does not flow into the South East? • Milford – South West? • Storage – South West? • Other stress tests as required • Off peak analysis required to refine investment options and predict plant usage
Flex Capacity Uncertainties • Modelled Transiently • (hour by hour) • Sensitivities • Similar supply uncertainties to flat • Include wider supply variations • Supply profiling considered • Allocation within existing and planned capability • No specific investment
Pressure • Pressure capability is output of flat and flex capacity analysis. • Sensitivities • Need to consider long run requirements for flat and flex • Seasonal variations • Operational configurations
S1 S1 S1 S2 S2 S2 S7 S7 S7 S3 S3 S3 S6 S6 S6 Capability Analysis Investment Planning Analysis Identification of Scenarios S4 S4 S4 S5 S5 S5 Optimal Investment Plan Development of optimal investment plan • Optimal investment plan considers range of supply and demand cases and other available options e.g. constrained LNG, buyback • Existing investment projects are kept under review • Sanctioning of new entry investment projects undertaken on strength of long-term auction signals • Sanctioning of new exit investment projects undertaken after user commitment received (currently through ARCAs)
Summary • Base Case view of supply and demand outlook for the planning horizon developed after industry consultation through the TBE process • Further supply cases are required for planning due to the diversity and uncertainty surrounding future supplies to the UK and to test localised adverse supply patterns for exit • Further demand cases are required to ensure NTS meets 1 in 20 peak day requirement • TBE and OCS Demand data is analysed • Analysis conducted for peak and off-peak conditions • Investment projects are determined by considering • Reinforcement across supply scenarios for different demand conditions • Other options not requiring capital investment • Long-term signals from users