Two more utilities join the Western Energy Imbalance Market

March 2, 2022
Addition of Avista Utilities and Tacoma Power will enhance grid efficiencies

FOLSOM, Calif., March 02, 2022 (GLOBE NEWSWIRE) -- Avista Utilities and Tacoma Power, two utilities serving a combined 600,000 electric customers in the Pacific Northwest, are the newest members of the Western Energy Imbalance Market (WEIM), with both beginning their participation today.

Avista Utilities, which serves more than 400,000 electric customers in Washington and Idaho, and Tacoma Power, a publicly owned utility serving nearly 200,000 electric customers in the Tacoma, Washington area since 1893, are the first of four utilities joining the real-time energy market in 2022.

Bonneville Power Administration and Tucson Electric Power will become active WEIM participants later this year. Once all four utilities have joined, the WEIM will have 19 members serving nearly 77% of the demand for electricity in the Western United States.

“I am pleased to welcome Avista and Tacoma Power to the Western Energy Imbalance Market,” said ISO President and CEO Elliot Mainzer. “Their participation during this dynamic time in the evolution of the Western energy landscape will offer meaningful benefits to their customers through enhanced operational efficiencies and the integration of clean energy resources into the power grid.”

The WEIM uses sophisticated technology to find and deliver the lowest-cost energy to its members, while enhancing reliability and providing significant environmental benefits through the reduction of renewable energy curtailments during periods of oversupply.

Reducing curtailments leads to lower greenhouse gas emissions because the renewable energy - rather than going unused - can be deployed by other market participants, and may displace power generated using fossil fuels.

“Joining the Western Energy Imbalance Market expands our ability to integrate more renewable energy while continuing to meet the energy needs of our customers, reliably and affordably,” said Jason Thackston, Avista’s senior vice president of energy resources. “It’s one more way we are working toward our goal of serving customers with 100% clean electricity by 2045 and 100% carbon neutral resources by 2027.”

“Gaining first-hand experience with centralized markets will better prepare us to engage in regional discussions about expanding such markets to advance our service delivery in safe, reliable, affordable, environmentally-friendly ways,” said Clay Norris, WEIM sponsor and Power Manager for Tacoma Power.

With the addition of these new participants, the WEIM will continue to provide increased economic and reliability benefits through the real-time transfer of energy. Additionally, the market’s resource diversity is expected to help soon push the cumulative benefits to WEIM entities to more than $2 billion.

While more utilities join the WEIM, the ISO is working to build on its success through the development of an Extended Day-Ahead Market, where the majority of energy transactions occur for participants. The stakeholder initiative process, which began in January, has established three working groups each focused on a market component that is instrumental in building a proposal that will meet the needs of the ISO’s partners in the West.

For information about the real-time energy market’s participants, quarterly benefits, governance, initiatives and upcoming meetings, visit the WEIM website.

About Avista Utilities
Avista Utilities is involved in the production, transmission and distribution of energy. We provide energy services and electricity to 403,000 customers and natural gas to 369,000 customers in a service territory that covers 30,000 square miles in eastern Washington, northern Idaho and parts of southern and eastern Oregon, with a population of 1.7 million. Avista Utilities is an operating division of Avista Corp. (NYSE: AVA). For more information, please visit

The Avista logo is a trademark of Avista Corporation.
SOURCE: Avista Corporation

About Tacoma Power
Tacoma Power is a division of Tacoma Public Utilities. Publicly owned since 1893, Tacoma Power provides electric service to nearly 179,000 customers in Tacoma, University Place, Fircrest, and portions of Fife, Lakewood, Federal Way, Steilacoom, Joint Base Lewis-McChord, and unincorporated Pierce County, as far south as Roy. For more information, visit

California ISO Media Email |
250 Outcropping Way | Folsom, California 95630 |
The California Independent System Operator (ISO) is a nonprofit public benefit corporation dedicated, with its partners, to continuous improvement and secure operation of a reliable grid operated for the benefit of consumers. It provides comprehensive grid planning, open and nondiscriminatory access to one of the largest networks of high-voltage transmission power lines in the world, and operates a $9 billion competitive electricity market. Recognizing the importance of the global climate challenge, the ISO is at the forefront of integrating renewable power and advanced technologies that will help provide a sustainable energy future efficiently and cleanly.

The Western Energy Imbalance Market (WEIM) is a real-time wholesale energy trading market that enables participants anywhere in the West to buy and sell energy when needed. The WEIM Governing Body is the governing authority designed by regional stakeholders and has shared authority with the ISO Board of Governors to resolve rules specific to participation in the WEIM.

Media Email

For more information, contact:
Vonette Fontaine |
Anne Gonzales |
Annie Gannon |
Rebekah Anderson |

Primary Logo

Source: Avista Corporation

Print Page
Email Page
RSS Feeds
Email Alerts