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Confederated Tribes of the Warm Springs Reservation - 2007 Project

Project Overview
Tribe/Awardee: Warm Springs Reservation, Confederated Tribes of the
Location: Warms Springs, OR
Project Title: Wind Energy Development at Mutton Mountain
Type of Application: Feasibility
DOE Grant Number: DE-FG36-07GO17077
Project Amounts:
DOE: $150,000
Awardee: $72,816
Total: $222,816
Project Status: See project status
Project Period
of Performance:
Start: September 2007
End: December 2008


Warm Springs Power and Water Enterprises (WSPWE) is a corporate entity owned by the Confederated Tribes of the Warm Springs Reservation, located in central Oregon. The organization is responsible for managing electrical power generation facilities on tribal lands and, as part of its charter, has the responsibility to evaluate and develop renewable energy resources for the Confederated Tribes of Warm Springs. WSPWE recently completed a four-year wind resource assessment of tribal lands. The study identified the Mutton Mountain site on the northeastern edge of the reservation as a site with sufficient wind resources to support a commercial power project capable of generating over 120,000 MWh per year. Initial estimates indicate that the first phase of the project would be approximately 40 MW to 75 MW of installed capacity.

The next phase will be to develop a detailed cost estimate for the proposed project that could be used to support project financing. WSPWE will conduct a 12-month cost-estimating study for the Mutton Mountain project. A detailed cost estimate is now needed to accelerate the development of the Mutton Mountain wind project. The costs and risks associated with various project layouts, access roads and equipment choices must be identified and estimated in order for the tribes to be in a position to make informed decisions regarding project economics and benefits.

Project Description

The tribe has conducted a comprehensive wind energy assessment of the reservation. This assessment evaluated multiple locations and identified the Mutton Mountain site as having sufficiently high and consistent wind potential to support a commercial wind energy project. Two years of monitoring at the Mutton Mountain site with multiple anemometers has confirmed that sufficient wind energy potential is present.


In order to fully assess the economic benefits that could accrue to the tribe through wind energy development at Mutton Mountain, a more detailed preliminary engineering assessment is needed to define the costs associated with key construction aspects of the project. This feasibility study will be used to determine the viability of an economically sustainable wind power generation facility at Mutton Mountain. The power will be generated from facilities on tribal lands and will be exported to generate revenue. The scope of work proposed will expand and build on a previously conducted resource assessment. The feasibility study will result in a comprehensive business plan for WSPWE’s wind project at Mutton Mountain. The information will support negotiations over power sales agreements, engineering contracts and construction contracts.

WSPWE proposes to conduct a 12-month comprehensive conceptual engineering study and cost estimate for the development of a 70 MW to 150 MW wind power project at locations on tribal lands in the Mutton Mountains. A project team consisting of WSPWE staff, Warm Springs Department of Natural Resource staff, researchers from Oregon State University and consultants has been assembled to complete a comprehensive preliminary engineering study and cost estimate for a commercial-scale wind project. The power from this project would be sold into the regional market for export from the reservation.

This proposal has as its objective to further define these project risks in order to provide the tribal council with an accurate estimate of the development cost. The proposed scope of work will define the Mutton Mountain project costs and economics in sufficient detail to allow the tribe to either build the project themselves or contract with a developer under the most favorable terms possible for the tribe.

To accomplish this objective the project team has established four primary goals:

  1. Complete a preliminary conceptual design sufficient to define the costs and risks associated with key elements of project construction. This scope of work does not include detailed project engineering. It does include conceptual design and development of specifications in sufficient detail to accurately estimate cost.

  2. Prepare detailed cost estimates of capital requirements and operation and maintenance costs for the initial phase of the Mutton Mountain project based on the conceptual design and alternative transmission routes.

  3. Identify issues where additional engineering or geotechnical investigations are needed to define the project design and estimate the cost to complete additional engineering or geotechnical studies that may be required to support project financial documents.

  4. Prepare a detailed project description and design specification document that can be used in a subsequent development phase for:

    1. Preparing the project description documents for the National Environmental Policy Act analysis
    2. Preparing the specifications documents for an engineer-procure-construct contract for detailed engineering and construction of the Mutton Mountain project
    3. Preparing the project pro forma and risk analysis documentation required for project financing or joint development agreements
    4. Negotiating the terms and conditions for the project's power sales agreement and interconnection agreements.


In order to advance the wind energy development to a stage where the tribe can evaluate the risk of development through WSPWE or through a joint venture or other agreement with a nontribal entity, a preliminary conceptual design and detailed cost estimate that would be completed as part of this scope of work would be used to support project financing. This cost estimate needs to be based on design criteria that use the resource data from Mutton Mountain and a preliminary conceptual design that considers site-specific aspects of the Mutton Mountain project site, which has a high degree of unknown risk factors.

The recent studies for the Mutton Mountain project have identified several key aspects of the development that need more detailed cost analysis in order to realistically estimate the total cost of the development. These key aspects of the project design and development which require further definition and more accurate cost estimates are:

  • Access road improvements and new road construction required for development
  • Transmission line route cost analysis for the two alternative routes
  • Substation improvement requirements for power export
  • Power plant equipment costs for different turbine options
  • Environmental assessment and licensing.

Project Location

Showcasing most of the Pacific Northwest's natural wonders, the Warm Springs Reservation includes Alpine lakes, pristine rivers, deep canyons and vistas of high desert and volcanic peaks. Over half the reservation is forested with the remainder primarily range land. Reservation lands extend from the summit of Oregon's Cascade Mountains and snowcapped Mt. Jefferson at 10,497 feet east to the Deschutes River's elevation at 1000 feet, with the Metolius River and Lake Billy Chinook forming the southern boundary.

Project Status

This project is complete. For details, see the final report. The project was competitively selected under the Tribal Energy Program's fiscal year 2007 solicitation, "Feasibility of Renewable Energy Projects on Tribal Lands," and started September 2007. For more information, see the project status report from November 2007.

For current project status or additional information, contact the project contact.

Project Contact

Jim Manion
General Manager
Warm Springs Power and Water Enterprises
P.O. Box 960
Warm Springs, OR 97761
Phone: 541-553-1046