Resurrecting ALoad Research Program Susan RomerNSTAR2006 AEIC Load Research ConferenceSeptember 2006

NSTAR TerritoryNSTAR Electric

NSTAR Gas

Combined Gas & ElectricMassachusetts 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 - ElectricThree Electric Operating CompaniesBoston Edison Company (BECO)Commonwealth Electric (COMM)Cambridge Electric (CAMB)

4,959 MW Peak Load (08/02/06-4 PM)23,236 GWh 2005 Annual Energy17% Share of ISO-New England Load

Load And Customers Served by 13 Competitive Suppliers as of July 200647% of load(Industrial 77%; Commercial 28%; Residential 16%)18% of customers (Industrial 59%; Commercial 26%; Residential 17%)

Wheres Load Research1993-1998Homeless1993Dismantled1999Sales??Load Research1980-1993RatesPURPA Baby2005Load Services2000Energy SupplyFinance & Accounting > Energy Supply > Load Services > Load Research 1 Analyst > Load Settlement & Load Response 3 Engineers

Detour ImpactLoss 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 othersLoad Research1992 - 10 Year Rate Freeze1993 - MA Electric Deregulation1999 - Merger2000> - Management Changes

Regulatory RequirementsContinuous 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

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

Opportunities

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

Load Settlement & Load ResearchDetermine 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 FailuresLoad Profiling Error** Sample EstimatesAccounting Error Billing EstimatesDistribution Loss Estimation Error Incorrect Loss FactorsTheftUn-metered Energy Company Use

Revenue Annually @$2 Billion

Load Research ProgramAssessment ObservationsAge 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 ProceduresOver 50% Indoor MetersDont Really Need THOSE Meters

Relative Precisions Averaged from 20-30%

Sample Augmentation PlanWe Need To Consider Options To Improve The Sample Results Until The New Samples Are Installed.

Techniques

Ratio EstimationTakes Advantage Of The Correlation Of The Variable Of Interest With Another Variable To Increase Precision Post StratificationCan 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 TransferA 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 Results2 Primary GoalsTo Improve the Current Sample Results in the InterimTo Use Ratio Estimation as an Expansion Methodology

Tested 2 Samples for July 2005Commonwealth Residential R-1Commonwealth Small General Service G-1 Looked At Relative PrecisionsRatio Estimation Versus Mean-Per-UnitRatio Estimation Versus Ratio Estimation Post-Stratified

Did Not Look At Load Data Transfer, Yet

Residential R-1 Relative Precisions MPU Vs. Ratio EstimationImproved Average Relative Precision From 16.33 to 13.10

Small GS G-1 Relative Precisions MPU vs. Ratio EstimationImproved Average Relative Precision From 25.72 to 11.17

Post StratificationAssignment DistributionResidentialR-1Small General ServiceG-1

StrataOriginalAssignmentPost StratifiedAssignment12021225233253042521

StrataOriginalAssignmentPost StratifiedAssignment12836224213272642824

Residential R-1 Relative PrecisionsRatio Estimation Post-StratifiedImproved Average Relative Precision From 13.10 to 10.97

Small GS G-1 Relative Precisions Ratio Estimation Post StratifiedImproved Average Relative Precision From 11.17 to 9.83

Relative Precision RangesReduction in Variability in the Precision Values

ResidentialSmall General ServiceMean Per Unit10.4 - 34.317.9 - 38.3Ratio07.9 29.205.9 30.8Ratio Post Stratified06.5 20.206.5 25.0

New Sample DesignsObjectivesAchieve 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 ProgramDo 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 BECOs G-2 Commercial And G-2 Industrial? No

Proposed13 Sampled Rates@2002 Sample Meters11 100% Monitored Rates (TOU)@4400 Meters@225 Interchange Meters

Current SamplesBECOCOMMCAMBTOTALR-1109100140349R-1-WH102102R-29999R-31389064292G-00G-1115120124359G-20G-2C9090G-2I90907433103281381

New SamplesBECOCOMMCAMBTOTALR-1220176160556R-2828880250R-3161165165491G-1200165198563G-2160 160 8235946032020

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

Re-Engineer To MonthlyProduction

Redesign and Install New SamplesBuild Sample Tracking SystemLoad ResearchRecast AnalysisUse Same Month Profiles For Settlement

Sharing Performance Metrics Between Metering, Meter Data Management, & Load ServicesSample Installation Rate; Data Retrieval Rate; Interval Meter CheckInstalling The New Samples 2006 and 2007Build a Sample Tracking System Improve Data Validation ProceduresRe-Engineer Load Profile Production to Monthly For SettlementImplement A Process Of Load Study Cycling And ReplacementCross Training Cloning the Old Fashion Way

Next Steps

Now, Whos Driving the Bus?Data Heaven

At NSTAR, the function of Load Research can better be described as

Wheres Waldo?

Massachusetts established strong regulations around load research in the early 1980s. These regulations continue to exist.

Yet, after a 1992 Rate Case where distribution rates were frozen for 10 years, NSTAR dismantled its Rates and Load Research areas.

Load Research had only one resource and no real home.

After a merger between Boston Edison and Com Energy in 1999, Load Research finally ended up in Energy Supply, but it did not have any real executive sponsorship. The impact of these over 10 years of detours left a load research program is extremely poor health.

Unable to Perform Statistically Valid Analysis Due To Significant Loss of DataTotal Data Loss by CompanyBECO - 47% Data LossCAMB - 28% Data LossCOMM - 14% Data Loss

Our Profiling Error On Average 20% Profiling Error Should Be < 10%

i.e. August 2005 Settlement Month = August 2005 Load Profiles NSTAR Uses 2003 Load Profiles

Sample Ages: > 8 years

Sample Sizes are not adequate

Accuracy Levels average @20%Statistical validity compromised by:loss of data Up to 47% loss due to non-installation, and later meter readsbias installation procedures

Meter data & sample administrationad hoc with duplication in effortdo not effectively monitor the samples & measure the success of program

Data validation, editing and estimation processes not standardized

Opportunities raised awareness of deficiencies in the load research program.

To get the message outGet exposure of the true situation with Senior Management and provideThem understanding of the importance of these meters.Unaccounted For Energy is likely to become increasingly contentious and subject to scrutiny by stakeholders

A 0.5% improvement in allocation equates to over 60,000 MWhs or $4.2 Million (@ avg. LMP $70) less exposure annually.

Have a quality, compliant, and maintainable load research program with statistically accurate sample studies that meet the daily requirements of load estimation & forecasting

Lower risks of disputes in