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UtilityForecasting & Planning

MADRI Meeting

March 7, 2006

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Purpose

This presentation is intended to be a general outline of utility forecasting and planning techniques not specific to any one company.

It is, however, intended to represent a utility that is a PJM member, and is following a process that works with the PJM planning regime.

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Planning Criteria

A utility’s planning criteria are intended to be a guide to provide for the safe, reliable and low cost development of the utility’s electrical system as loads increase and reinforcements and/or new facilities are required.

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Basic Principles

With all facilities in service: Load must be within normal equipment

ratings Must provide acceptable voltages

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Basic Principles

With the outage of any single piece of equipment (N-1 Criteria Violation): Affected load must be within the emergency

rating of the remaining facilities System must provide minimum emergency

voltages

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Basic Principles

N-1 criteria are applied in a similar fashion to: Substations Distribution Facilities Subtransmission Facilities Transmission Facilities

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Basic Principles Transmission Planning Criteria

Goes beyond N-1 N-2 (After the N-1 outage and re-

adjustment, loss of an additional element.) Towerline outages Stuck breakers

Transmission planning criteria are more restrictive than operating criteria to account for potential new generation, and network facilities’ forecasted and unplanned outages.

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Distribution Planning Load Forecasting

Substation Feeder

Distribution Circuit Reinforcement Ratings N-1 Criteria

New Business Connected vs. Estimated Loads Load Build-up Schedules Load Shifting

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Substation Forecast/Planning Process Diagram for a Typical Utility

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Substation Forecast/Planning ProcessData Collection

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Substation Forecast/Planning Process Data Collection

CMMS Peak Load Data MV-90 Remote

Metering Substation Data

Concentrators Inspection Data Data “Scrubbing”

Adjustments Voltage Reduction,

Cogen, etc. Reference Data

Station Type, Reactive, Power Factors, Feeder Info, etc.

Load Transfers Historical Trends Peak Adjustments

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Substation Forecast/Planning ProcessWeather Normalization

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Substation Forecast/Planning ProcessWeather Normalization

Weighted Temperature-Humidity Index (WTHI) 3-Day Heat Build-Up 10-5-2 Weighting

Factors

Normalization Standard 50/50 Historical

Probability 84 Degrees WTHI

Normalized Peak Selection Load vs. WTHI

Correlation Exclusion of Data

Points Below 73 Degrees WTHI

Exclusion of Non-Trend Data Points

Current Year Weather Sensitivity

5-Year Weather Sensitivity

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Substation Forecast/Planning ProcessSubstation & Area Forecasts

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Substation Forecast/Planning ProcessSubstation & Area Forecasts

Growth Factors General Growth – Load growth

of existing and small additional customers is generally consistent with historical trending

Specific Growth – Load growth attributable to major new business projects greater than 300 kW

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Diversified Specific Growth

Adjusted for:Over-estimation of LoadsLoad ProfilesDelayed Project CompletionsCustomer to Feeder CoincidenceFeeder to Substation Coincidence

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Coincidence Factor

Substations feed a number of different types of load

Not all of the load will peak at the same time (diversity)

Expect any implementation of time-of-use or RTP tariffs to cause interval customers to change/modify load patterns

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Substation Forecast/Planning ProcessSubstation & Area Forecasts

Forecast Worksheet Historical Trending Feeder Peak

Synthesis Forecast Performance

Short Range Forecast 4-Year Forecast

Long Term Forecast 9 Scenarios

High Tension Service Customer Forecasts Developed by utility

Area (Switching Station) Forecasts Coincidized

Substation Roll-Up System Forecast

Roll-Up Coincidized HV

Substation & Area Forecast Roll-Up

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Substation Forecast/Planning ProcessSubstation & Area Planning

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Substation Forecast/Planning ProcessSubstation & Area Planning Substation & Area

Capacity Firm N-1 Criteria Includes Automatic ICT

Transfers Capacity Processing

Load vs. Capacity Analysis

Load Relief Modeling Power Factor

Correction Load Transfers Dispersed Generation

System Reinforcement Modeling Interstation

Capacity Ties Station

Reinforcement New Station Generation (As

Permitted)

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Feeder Forecast ProcessData Acquisition

Substation Operators collect data during station inspections via a Mobile Data Terminal (MDT)

Data is electronically uploaded into CMMS Data is extracted into spreadsheet Data is scrubbed – no data, broken meter, tie

recloser operations, etc. Summer peak load is selected and utilized to

develop the individual feeder forecasts

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Feeder Forecasting ProcessLoad vs. Capacity Analysis

Peak data is used for Station Feeder Forecasts (Feeder Utilization)

Data is processed to evaluate overloaded circuits

Forecast sheets are used when a New Business Plan of Supply is submitted Is capacity available? If not, how can circuit be relieved?

Reinforcement jobs and New Business jobs are tracked on the Station Feeder Forecast sheets

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How Do Projects Emerge?

Individual substation overloads are not as critical if sufficient ties exist

Greatest concern - area overloads consisting of two (2) or more substations

Could cause cascading overloads and area outages

Time to reinforce when area overloads are present or could reasonably be expected to occur in the near future

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New Business

Division Planners are typically concerned with new business projects 300-kVA and greater

Voltage / Service characteristics can range from secondary to sub-transmission (277/480 volts up to 69-kV)

Types of New Business can vary from Network Service to Substation / High Tension service

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Transmission Planning

Entity Load Forecast Regional Transmission Expansion Planning (RTEP) Process

Lead by PJM and coordinated with Transmission Owners Incorporation of utility’s T&D Planning results into PJM’s

RTEP Process, PJM will begin zonal forecasting utility loads this year

Baseline Reinforcements Merchant Generation/Transmission Interconnections &

Reinforcements Analyses & Tools

Short Circuit Load Flow System Stability LOLP (Loss of Load Probability)

Operations Support

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Entity Load Forecast

The Entity Load Forecast is an independent forecast of summer peak, performed by PJM

Used to set Zonal Scaling Factors in eCapacity and sets capacity obligations for all LSE’s

Relates growth in the PJM normalized peak to the U.S. economy (Gross Domestic Product)

This load is allocated to specific nodes using the various utility’s Distribution Substation Forecasts

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Any Questions?