Global Assumptions and Inputs

  • Global assumptions (and video, Sep 2024)
    Brief overview of the common assumptions used throughout modeling
    • Discount rate and financing assumptions (Feb 2025)
      Assume consistency across analyses (Workbook)
    • Transmission and distribution deferral assumptions (and video, Nov 2024) - note see workbook below for final values
      Methodology for valuing the ability of some resources to defer transmission and distribution builds (updated for each power plan) (Workbook Jan 2025)
  • Consistent treatment of resources (and video, Dec 2024)
    Methodology to ensure the consistent treatment of costs and benefits across all resources. (Cost Treatment Workbook)
    • Environmental methodology for new resources (and video, Sep 2024)
      A required part of the power plan and cost treatment of resources, we outline the Council’s methodology for determining and quantifying environmental costs and benefits associated with new resources
  • Existing policies (and video, Jan 2025)
    The Council plans assuming utilities, states, and the region meet all stated existing policies and goals. Finalizing the list of policies must be done early in the planning process in order to align assumptions. Uncertainty around future policies may be analyzed in scenario analysis.
  • Outside the Northwest Loads and Resources (and video, April 2025)
  • Proposed Final Adequacy Criteria (and video, April 2025)

Resources

  • Proposed Conservation Resources
  • Proposed Reference Plants for the Ninth Plan

 

Forecasts

  • Natural gas and coal price forecasts (and video, Feb 2025)
    Natural gas and coal are two fuels for the Northwest power system, and therefore the Council must develop a forecast of future prices. Natural gas prices were low in 2024, but there have been periods of volatility and higher prices throughout the past decade.

    • Ninth Plan Natural Gas Price Forecast (Workbook Mar 2025)

Climate and environment