IBM新奥燃气控股集团—OverviewofChargingCalculationModelsFinal.ppt

Gas TCMF,National Grid House,Warwick,24th January 2006,Agenda,1)Introductions2)Minutes of Previous Meeting3)Terms of Reference4)Objectives of Meeting5)Overview of Charging Arrangements6)Overview of Charge Calculation Models7)1 April 06 Charge Revisions8)Way Forward9)Any Other Business,Agenda,1)Introductions2)Minutes of Previous Meeting3)Terms of Reference4)Objectives of Meeting5)Overview of Charging Arrangements6)Overview of Charge Calculation Models7)1 April 06 Charge Revisions8)Way Forward9)Any Other Business,Transport Models,Contents Transport Models,LRMC Methodology Brief introduction to:Graphical FalconTranscostPractical demonstration of TranscostHow it fits into the LRMC Methodology,Aims of the LRMC Methodology,Derives forward-looking charges,which are intended to provide economically efficient signals to systems usersIncentivises Users to locate power stations or introduce new fields in areas which will result in minimum reinforcement to the NTSProvides locational pricing signals,Application of LRMC for Gas Charging,Establish Base CaseCalculate cost of providing capacity above base caseNo assumption can be made on where demand for capacity will arise(in the methodology)LRIC Methodology extends LRMC Methodology,so results need to be scaleable,NTS Exit Capacity Charge Process,LRMC matrix for all entry-exit pairs,Scaling/Rebalancing Rules,Reflective LRMCs for each entry and each exit point,Exit Capacity Charges,Solver,Several stages and tools are involved in the Pricing process,even to generate administered prices,Entry Incremental Pricing Process,IECR Methodology,Entry Capacity Incremental Prices,Solver,for increments up to 12 mscm,LRICs are generated from multiple Transcost/Solver analyses and also FALCON analyses for larger increments,for increments over 12 mscm,Transcost process,Supply/Demand Scenariofor Year 1,Current Network+Known Reinforcements in Year 0,Marginal Reinforcement Costs for Year 1,Reinforced Base Network forYear 1,LRMC/LRIC matrix,Reinforcements sufficient to meet 1 in 20 demand,Reinforcements sufficient to meet chosen increment,LRMC Generation-Graphical Falcon,Graphical Falcon(“Fast Analysis of Large Constrained Networks”)Primarily a network analysis tool for system planning,which was also used for generating LRMCs Takes the following into account:-Length&diameter of actual pipelines-Compressor efficiencies-Types of valves-Altitude of pipework-Pipe burial depth-Thermal conductivity of soil-etc.,LRMC Generation-Graphical Falcon,Graphical Falcon is an accurate,but a complex engineering based modelling tool Complexity cause several issuesRequires a large degree of time and analysis resourceData intensive requires pre and post processingRequires expert judgement,LRMC Generation Why develop Transcost?,Transcost was designed to simplify the LRMC processIntroduction in 1998 Benefits(compared to Graphical Falcon)Procedure time-20 wks down to 60 minsEngineering judgement simplified improving repeatabilityAll entry&exit routes are analysed identifying independently least cost route for each entry and exit pointExtrapolation removed marginal cost derived for all 10 years(as opposed to years 1,3 and 7 used in Graphical Falcon),Transcost-Flow Assumptions,Pipes,Compressors&Regulators simplified for example:Graphical Falcon applies full Panhandle equation!Transcost uses simplified Panhandle equation for pipe flows P12 P22=klq2/d5where k=1.2335x1013,(P=pressure,l=length(km),q=flow rate(mcmd),d=diameter(mm)NTS flows and pressures remain constant steady state Reinforces existing network with like for like,Transcost-Cost Assumptions,Investment costsPipeline reinforcement costs per km=(A x diameter(mm)+B A based on steel pricesB constant based on operations costsCompressor-Greenfield:30m per stationCompressor-Existing:15m per stationProject Management costs 15%of investment costOperating costs 1.5%of investment cost,Inputs-(Static File)Asset Data,NTS Configuration Data for next 10 years Parameters,Nodes,Regulators,Compressors&Pipelines max/min pressure fixed costs&project management costs chosen increment X&Y co-ordinates of inlets,regulators&compressors Regulator state(on-open-closed)Compressor Max Power,Efficiency,Gas Compressibility,Inlet Temp,Fuel Usage,Inlet&Outlets pressures Pipeline dia(mm)&length(km),Inputs(Variable File)Operational Data,Flow Data for 10 yrs,(peak day supply/demand)Nodes,Regulators&Compressors 10 yrs of NTS Max&Min pressure Linepack constraints Calorific Value data Network flow data Forecast supply and demand(GWh)for each entry point and offtake for years 1 to 10 based on a 1 in 20 peak day supply/demand flow rateUtilising data from TBE and 10yr Statement,Transcost Process Demonstration,1 Open package and set up Log file2 Base Network is constructed using Static&Variable file data 3 User manually optimises regulator settings to produce min.level of base network reinforcements4 Run Marginal costs to generate costs for each entry/exit pair5 Move to Yr 2 using Yr 1 a base network and return to step 3.6 Repeat until all 10 yrs calculated-saving all modifications to the log file7 Calculate LRMCs&Exit Transcost,Tariff Model,Why is Solver required?,Point-to-point charges are impractical to administer for a“large”system like the NTSCan also result in the“portfolio effect”whereby larger shippers can benefit by rearranging their portfolio in such a way that they pay minimal chargesNeed a set of charges to allow entry and exit at any point on the NTS,without notification of the route being requiredSolver fits the data in the LRMC(LRIC)matrix such that overall,any resulting entry charge and any exit charge can be added together to give a close approximation to the cost of providing entry and exit capacity for that pairing of nodes,How does Solver fit LRMC(LRIC)data?,Transcost generates a log file which contains the LRMC(LRIC)matrixThe matrix is imported into Excel.The Solver Add-in is configured to perform a least squares optimisation i.e.we want(for all entry-exit combinations)entry charge+exit charge LRMC value for that entry and exit pair in the matrixBut,since there is always an error generated from this approximation,we want to keep the errors as small as possible One way of doing this is to find the set of values for entry and exit charges that gives the least error overall(“minimise the sum of the squares of the errors”)These values are called LRMC reflective charges in the Methodology Statement.They are also referred to as“unscaled LRMCs”.,Does Solver do anything else?,In order to be able to carry out the optimisation,Solver requires one more piece of information,otherwise there are many solutions that could be calculated(i.e.any solution found will not be unique and may not be reproducable)This is supplied by constraining all the reflective charges that are calculated to be positive and non-zero,Example Solver,(this slide contains the embedded Excel file,which can be viewed by double-clicking the icon),NTS Exit Capacity Charge Scaling and Re-balancing,Rules are applied to allow revenue recovery and stabilise charges“Scaling”required to ensure revenue recovery“Rebalancing”limit year on year changes in chargesInitially,the charges resulting from the Solver tool are scaled to meet 50%TO Allowed RevenueRe-balancing looks at the trends of the charges generated by the Solver tool,after they have been scaledScaling performed before re-balancing(PC71,November 2001)in order to counteract the effect of a large increase in TO target revenue at that timeThis was the last time charges were re-balanced(PC76,November 2002),Re-balancing Rules,Step 1:the latest set of scaled LRMCs are obtained from Transcost/Solver/Scaling processesStep 2:these are compared to previous set of scaled LRMCs and the current exit capacity charges for each point in turn.Note that the current exit capacity charges dont necessarily equal the previous scaled LRMCs due to re-balancing which has taken place in previous years.Exit charge is less than both scaled LRMCs:move charge to minimum scaled LRMC,Re-balancing Rules,Step 2 continued:Exit charge is more than both scaled LRMCs:move charge to maximum scaled LRMC,Exit charge is between scaled LRMCs:do not adjust chargeStep 3:Cap any change in charges from their scaled value(+/-30%used in April 2002)to obtain final charge,Gas TCMF,24th January 2006,青苹果出品 必属精品http:/,囊括2007-2010几百G地产策划资料/企业管理人力资源全套/品牌策划资料/行业分析报告/PPT模板等。,