Tiered Rate Methodology (TRM) Studies

TRM not only impacts the overall level of power supply costs, but may also require modifications to utilities’ cash flow management, cost allocations and rate designs. Demand and load shaping charges can result in significant variability in monthly power supply costs. In addition, the TRM rate structure includes changes that may impact the allocation of costs among utilities’ customer classes. As utilities’ loads grow it will become very important to consider how utilities’ Tier 1 allocations are shared among new and existing retail customers. EES Consulting has assisted utilities in evaluating whether or not the TRM wholesale rate design should be carried over into retail rate setting.

Northwest Studies

Below are a few of the Northwest utilities that EES Consulting has assisted with TRM-related power supply and rate design issues in the last few years:

  • Benton County PUD
  • Benton Rural Electric Association
  • Blanchly-Lane Electric Coop
  • Canby Utility
  • Central Electric Cooperative
  • Central Lincoln People’s Utility District
  • City of Bonners Ferry
  • City of McMinnville
  • City of Port Angeles
  • City of Richland
  • Clark Public Utilities
  • Clearwater Power
  • Columbia River Electric Association
  • Douglas Electric Cooperative
  • Emerald People’s Utility District
  • Fall River Rural Electric Cooperative
  • Inland Power and Light


  • Kittitas PUD
  • Lower Valley
  • Lewis PUD
  • Mason County PUD #1
  • Midstate Electric Cooperative
  • Missoula Electric Cooperative
  • Northern Lights, Inc.
  • Northern Wasco
  • Okanagan REA
  • Pacific County PUD
  • Ravalli County Electric Coop
  • Salem Electric
  • Salmon River
  • Skamania County PUD
  • Tanner
  • Tillamook PUD
  • Wasco Electric Cooperative

Featured Projects

Box Canyon Project Studies

Public Utility District No. 1 of Pend Oreille County, in Washington state, selected EES Consulting as the lead consultant for relicensing studies for the Box Canyon Hydroelectric Project.  The relicensing involved numerous engineering and resource studies.  EES Consulting staff members performed studies and managed and coordinated activities of consultants and subconsultants who conducted engineering and environmental studies for project license amendment and relicensing.

Grays Harbor PUD Integrated Resource Plan

EES Consulting prepared Grays Harbor’s 2020 Integrated Resource Plan. Grays Harbor is required to submit an IRP to the state of Washington every two years that demonstrates how it will meet the electric power needs of its members with a reliable supply of power delivered in the most cost-effective manner. The 2020 IRP was an evaluation of resource alternatives that could be deployed to meet Grays Harbor’s load and meet state of Washington renewable energy requirements under the Energy Independence Act and carbon-free energy requirements under the Clean Energy Transformation Act. Grays Harbor embarked on an IRP to study alternative sources of supply that could best serve its customers’ needs for the period 2021-2040.