1. 1 DPS Electricity Forecasting Historic Practices and Status of Current Plans Sept. 13, 2005 Informational Workshop Docket 7081 J. Riley Allen

2. 2 Topics DPS forecasting approach and methods DPS forecasting approach and methods DSP plans for updating its forecasts DSP plans for updating its forecasts Open issues Open issues

3. 3 Overview of Current Practices The Department’s electricity forecast is a forecast built up from 3 independent efforts The Department’s electricity forecast is a forecast built up from 3 independent efforts All Fuel Prices forecast/Avoided costs – Currently being finalized ICF (biennial)/Currently under development in connection with update of avoided costs. All Fuel Prices forecast/Avoided costs – Currently being finalized ICF (biennial)/Currently under development in connection with update of avoided costs. Economic Forecast – Regional Economic Modeling, Inc., (equilibrium model) Economic Forecast – Regional Economic Modeling, Inc., (equilibrium model) Energy System Dynamics – Platform is being migrated from existing Promula base to VENSIM (interim use of econometric model) Energy System Dynamics – Platform is being migrated from existing Promula base to VENSIM (interim use of econometric model)

4. 4 Structural Model (Energy) System Dynamics (historically E2020) – Allows simulation of the world as it works with feedback loops. System Dynamics (historically E2020) – Allows simulation of the world as it works with feedback loops. Policy Simulation -- What ifs and structural changes Policy Simulation -- What ifs and structural changes Flexibility -- Flexibility to exchange key inputs with other models (REMI, Fuel prices) Flexibility -- Flexibility to exchange key inputs with other models (REMI, Fuel prices) Consistency – Allows consistency with other forecasts of BEA, Vermont, and EIA (or other fuel price forecasts) Consistency – Allows consistency with other forecasts of BEA, Vermont, and EIA (or other fuel price forecasts) Bottom up -- Ability to develop forecasts that have both top-down and bottom-up consistency. Bottom up -- Ability to develop forecasts that have both top-down and bottom-up consistency.

5. 5 Structural Model (Economy) Economic (equilibrium model, REMI) Economic (equilibrium model, REMI) Regional economic model (can be national, regional, state or local) Regional economic model (can be national, regional, state or local) Relied on by state to generate forecast of the economy for budget projections; Relied on by state to generate forecast of the economy for budget projections; Impact analysis (what if’s and impacts of structural changes on fuel forecasts and feedbacks) Impact analysis (what if’s and impacts of structural changes on fuel forecasts and feedbacks)

6. 6 Why structural models? Flexibility and Policy Simulation Flexibility 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 scenario analysis) Uncertainty analysis (flexible tool for what if’s and scenario analysis) Forecasting Accuracy (???) Forecasting Accuracy (???) The tool allows one to capture significant influences that did not exist or were not significant in historical data. The tool allows one to capture significant influences that did not exist or were not significant in historical data. Depends on commitment to detail and maintenance. Depends on commitment to detail and maintenance.

7. 7 DPS Schedule All Fuel Price forecast/Avoided Costs (ICF analysis) All Fuel Price forecast/Avoided Costs (ICF analysis) Finalized in September 2005 Finalized in September 2005 Economic Analyst/Forecasting (Sept ’05) Economic Analyst/Forecasting (Sept ’05) Economic Projections (January/February 2006) Economic Projections (January/February 2006) Statewide electricity forecast incorporating economic forecast (January/February ’06) Statewide electricity forecast incorporating economic forecast (January/February ’06) System dynamics forecast (Aug/Sept ’06) System dynamics forecast (Aug/Sept ’06)

8. 8 Open Issues Local versus statewide -- Current DPS forecast is typically Statewide (Local forecasting) Local versus statewide -- Current DPS forecast is typically Statewide (Local forecasting) Harmonization/Reconciliation -- Relationship between DPS forecast and VELCO/ISO-NE forecast and individual utility forecasts; Harmonization/Reconciliation -- Relationship between DPS forecast and VELCO/ISO-NE forecast and individual utility forecasts; DPS Role as Advocate and Planner -- DPS as advocate in Board proceedings. Forecast is sometimes used by Vt. utilities in Board proceedings. DPS Role as Advocate and Planner -- DPS as advocate in Board proceedings. Forecast is sometimes used by Vt. utilities in Board proceedings. Information Sharing -- What information can be used or shared between the DPS and the utilities and EVT to improve forecasting and ability to identify impacts of DR? Information Sharing -- What information can be used or shared between the DPS and the utilities and EVT to improve forecasting and ability to identify impacts of DR? Uncertainty Analysis -- Role of uncertainty analysis/alternative load scenarios Uncertainty Analysis -- Role of uncertainty analysis/alternative load scenarios

9. 9 Conclusion