240 likes | 344 Views
Resurrecting A Load Research Program. Susan Romer NSTAR 2006 AEIC Load Research Conference September 2006. NSTAR Territory. Massachusetts’ Largest Investor-owned Electric And Gas Utility Transmitting & Delivering Electricity & Natural Gas For More Than 100 Years
E N D
Resurrecting A Load Research Program Susan Romer NSTAR 2006 AEIC Load Research Conference September 2006
NSTAR Territory • Massachusetts’ Largest Investor-owned Electric And Gas Utility • Transmitting & Delivering Electricity & Natural Gas For More Than 100 Years • Serve @1.4 M Residential & Business Customers In Over 100 MA Communities • @ 3,200 employees NSTAR Electric NSTAR Gas Combined Gas & Electric
NSTAR - Electric • Three Electric Operating Companies • Boston Edison Company (BECO) • Commonwealth Electric (COMM) • Cambridge Electric (CAMB) • 4,959 MW – Peak Load (08/02/06-4 PM) • 23,236 GWh – 2005 Annual Energy • 17% Share of ISO-New England Load • Load And Customers Served by 13 Competitive Suppliers as of July 2006 • 47% of load • (Industrial – 77%; Commercial – 28%; Residential 16%) • 18% of customers • (Industrial – 59%; Commercial – 26%; Residential 17%)
Where’s Load Research 2005 Load Services Load Research 2000 Energy Supply 1999 Sales?? 1993-1998 Homeless 1993 Dismantled 1980-1993 Rates PURPA Baby • Finance & Accounting • > Energy Supply • > Load Services • > Load Research – 1 Analyst • > Load Settlement & Load Response – 3 Engineers
Detour Impact 1992 - 10 Year Rate Freeze 1993 - MA Electric Deregulation 1999 - Merger 2000> - Management Changes • Loss of employees with knowledge • No senior management sponsor • No field commitment • “Those Meters Are Only Used For Research” • Data not available when needed • Load data gateway shifted to others Load Research
Regulatory Requirements • Continuous Load Research • Meet 95/10 Sample Results Accuracy Levels • Most Northeast Utilities Perform Load Research At 95/5 Accuracy Levels • Many Northeast Utilities Use Same Month Profiles For Settlement Month
Fear of Financial Exposure Senior Management Sponsorship = Opportunities • 2004 Rate Case and No Load Research Data • Awareness of ISO Settlement Dispute B/W Two Other Parties • Understanding of How Interchange Point Malfunction Can Impact the Calculation of System Loads • 2005 Energy Policy Act DST Change
Load Research Supports • Estimation of Competitive Supplier Loads and ICAP Values • Development of Rates Charged to Customers • Unbilled Energy Sales And Unbilled Revenues Balances • Billed/Unbilled Sales & Substation Forecasts • Accrual Of Purchased Power Expense As Compared to Actual • Development of Rates Charged to Customers • Local Network Service Billing for Wholesale Customers • Regional Network Transmission Billing for ISO • Development of Engineering Loss Studies
TOU Loads 45% Profiled Loads 55% Load Settlement & Load Research • Determine suppliers’ load obligations from load research • for the purposes of ISO-New England energy market settlement • A contributing factor to unaccounted for energy (UFE) • Metering Error – Meter Failures • Load Profiling Error** – Sample Estimates • Accounting Error – Billing Estimates • Distribution Loss Estimation Error – Incorrect Loss Factors • Theft • Un-metered Energy – Company Use • Revenue • Annually @$2 Billion
Load Research ProgramAssessment Observations • Age of the Samples - Over 9 Years Old • Significant Data Loss – 47% for BECO • Sample Sizes All Less than 30 Per Stratum • Sample Bias Caused By Installation Procedures • Over 50% Indoor Meters • “Don’t Really Need THOSE Meters” • Relative Precisions Averaged from 20-30%
Sample Augmentation Plan We Need To Consider Options To Improve The Sample Results Until The New Samples Are Installed. Techniques • Ratio Estimation • Takes Advantage Of The Correlation Of The Variable Of Interest With Another Variable To Increase Precision • Post Stratification • Can Be Used Within A Sample Study, But Can Also Be Utilized To Post Stratify Transferred Data From Another Utility With Similar Population Characteristics • Load Data Transfer • A Transfer of Load Data From One Distribution Company To Another Distribution Company For Certain Samples. Can Utilize Post Stratification To Fit The Transferred Data To The Sample
Preliminary Test Results • 2 Primary Goals • To Improve the Current Sample Results in the Interim • To Use Ratio Estimation as an Expansion Methodology • Tested 2 Samples for July 2005 • Commonwealth Residential R-1 • Commonwealth Small General Service G-1 • Looked At Relative Precisions • Ratio Estimation Versus Mean-Per-Unit • Ratio Estimation Versus Ratio Estimation Post-Stratified • Did Not Look At Load Data Transfer, Yet
Residential R-1 Relative Precisions MPU Vs. Ratio Estimation Improved Average Relative Precision From 16.33 to 13.10
Small GS G-1 Relative Precisions MPU vs. Ratio Estimation Improved Average Relative Precision From 25.72 to 11.17
Post StratificationAssignment Distribution Residential R-1 Small General Service G-1
Residential R-1 Relative PrecisionsRatio Estimation Post-Stratified Improved Average Relative Precision From 13.10 to 10.97
Small GS G-1 Relative Precisions Ratio Estimation Post Stratified Improved Average Relative Precision From 11.17 to 9.83
Relative Precision Ranges Reduction in Variability in the Precision Values
New Sample Designs Objectives • Achieve Design Accuracy Of +/- 5% At The 95% Confidence Level For All Hours Of The Year • Stay Within Budget Constraints • Use Stratifying Variables That Will Achieve The Targeted Accuracies For All Hours Of The Year • Utilize A 100% (Certainty) Stratum In The Design Process When Feasible • Have Longevity Of At Least Five Years • Represent Target Populations Optimally • Have A Minimum Of 30 Sample Points In Each Stratum • Minimize Sample Bias In The Installation Procedures
Current and Proposed Program • Do We Need A Separate Sample For R-1 Water Heating (WH)? No • Do We Need A Separate Samples For R-2? Yes • Do We Need Separate Samples For BECO’s G-2 Commercial And G-2 Industrial? No • Proposed • 13 Sampled Rates • @2002 Sample Meters • 11 100% Monitored Rates(TOU) • @4400 Meters • @225 Interchange Meters
Program Objectives • Have a quality, compliant, and maintainable load research program • Lower risks of disputes in regulatory proceedings and in ISO settlements • Minimize loss of data • Improve the predictability of costs of operations, maintenance, & future capital expenditures
Load Research Roadmap Load Research Use Same Month Profiles For Settlement Re-Engineer To Monthly Production Build Sample Tracking System Redesign and Install New Samples Recast Analysis
Next Steps • Sharing Performance Metrics • Between Metering, Meter Data Management, & Load Services • Sample Installation Rate; Data Retrieval Rate; Interval Meter Check • Installing The New Samples – 2006 and 2007 • Build a Sample Tracking System • Improve Data Validation Procedures • Re-Engineer Load Profile Production to Monthly For Settlement • Implement A Process Of Load Study Cycling And Replacement • Cross Training • Cloning the Old Fashion Way
Load Research Now, Who’s Driving the Bus? Data Heaven