11

DPS Electricity ForecastingDPS Electricity ForecastingHistoric Practices and Status Historic Practices and Status

of Current Plansof Current Plans

Sept. 13, 2005Sept. 13, 2005

Informational Workshop Docket Informational Workshop Docket 70817081

J. Riley AllenJ. Riley Allen

22

TopicsTopics

DPS forecasting approach and DPS forecasting approach and methodsmethods

DSP plans for updating its forecastsDSP plans for updating its forecasts Open issuesOpen issues

33

Overview of Current Overview of Current PracticesPractices

The Department’s electricity forecast is a The Department’s electricity forecast is a forecast built up from 3 independent effortsforecast built up from 3 independent efforts All Fuel Prices forecast/Avoided costs – Currently All Fuel Prices forecast/Avoided costs – Currently

being finalized ICF (biennial)/Currently under being finalized ICF (biennial)/Currently under development in connection with update of development in connection with update of avoided costs.avoided costs.

Economic Forecast – Regional Economic Economic Forecast – Regional Economic Modeling, Inc., (equilibrium model)Modeling, Inc., (equilibrium model)

Energy System Dynamics – Platform is being Energy System Dynamics – Platform is being migrated from existing Promula base to VENSIM migrated from existing Promula base to VENSIM (interim use of econometric model)(interim use of econometric model)

44

Structural Model (Energy)Structural Model (Energy)

System Dynamics (historically E2020) – Allows System Dynamics (historically E2020) – Allows simulation of the world as it works with simulation of the world as it works with feedback loops. feedback loops. Policy Simulation -- What ifs and structural changesPolicy Simulation -- What ifs and structural changes Flexibility -- Flexibility to exchange key inputs with Flexibility -- Flexibility to exchange key inputs with

other models (REMI, Fuel prices)other models (REMI, Fuel prices) Consistency – Allows consistency with other forecasts Consistency – Allows consistency with other forecasts

of BEA, Vermont, and EIA (or other fuel price of BEA, Vermont, and EIA (or other fuel price forecasts)forecasts)

Bottom up -- Ability to develop forecasts that have Bottom up -- Ability to develop forecasts that have both top-down and bottom-up consistency.both top-down and bottom-up consistency.

55

Structural Model (Economy)Structural Model (Economy)

Economic (equilibrium model, REMI)Economic (equilibrium model, REMI) Regional economic model (can be Regional economic model (can be

national, regional, state or local)national, regional, state or local) Relied on by state to generate forecast Relied on by state to generate forecast

of the economy for budget projections;of the economy for budget projections; Impact analysis (what if’s and impacts of Impact analysis (what if’s and impacts of

structural changes on fuel forecasts and structural changes on fuel forecasts and feedbacks)feedbacks)

66

Why structural models?Why structural models?

Flexibility and Policy SimulationFlexibility and Policy Simulation Building Standards;Building Standards; Appliance Standards;Appliance Standards; Efficiency Utility Programs;Efficiency Utility Programs; Cogeneration.Cogeneration.

Uncertainty analysis (flexible tool for what if’s and Uncertainty analysis (flexible tool for what if’s and scenario analysis)scenario analysis)

Forecasting Accuracy (???)Forecasting Accuracy (???) The tool allows one to capture significant influences that The tool allows one to capture significant influences that

did not exist or were not significant in historical data.did not exist or were not significant in historical data. Depends on commitment to detail and maintenance. Depends on commitment to detail and maintenance.

77

DPS ScheduleDPS Schedule

All Fuel Price forecast/Avoided Costs (ICF All Fuel Price forecast/Avoided Costs (ICF analysis)analysis) Finalized in September 2005Finalized in September 2005

Economic Analyst/Forecasting (Sept ’05)Economic Analyst/Forecasting (Sept ’05) Economic Projections (January/February Economic Projections (January/February

2006)2006) Statewide electricity forecast incorporating Statewide electricity forecast incorporating

economic forecast (January/February ’06)economic forecast (January/February ’06) System dynamics forecast (Aug/Sept ’06)System dynamics forecast (Aug/Sept ’06)

88

Open IssuesOpen Issues

Local versus statewide -- Current DPS forecast is typically Local versus statewide -- Current DPS forecast is typically Statewide (Local forecasting)Statewide (Local forecasting)

Harmonization/Reconciliation -- Relationship between DPS Harmonization/Reconciliation -- Relationship between DPS forecast and VELCO/ISO-NE forecast and individual utility forecast and VELCO/ISO-NE forecast and individual utility forecasts;forecasts;

DPS Role as Advocate and Planner -- DPS as advocate in DPS Role as Advocate and Planner -- DPS as advocate in Board proceedings. Forecast is sometimes used by Vt. Board proceedings. Forecast is sometimes used by Vt. utilities in Board proceedings. utilities in Board proceedings.

Information Sharing -- What information can be used or Information Sharing -- What information can be used or shared between the DPS and the utilities and EVT to shared between the DPS and the utilities and EVT to improve forecasting and ability to identify impacts of DR?improve forecasting and ability to identify impacts of DR?

Uncertainty Analysis -- Role of uncertainty Uncertainty Analysis -- Role of uncertainty analysis/alternative load scenariosanalysis/alternative load scenarios

99

ConclusionConclusion