Avista Utilities, Tacoma Power Join Western Energy Imbalance Market

Avista Utilities and Tacoma Power on March 2 began their participation in the Western Energy Imbalance Market (WEIM) operated by the California Independent System Operator Corp. The two utilities serve a combined 600,00 electric customers in the Pacific Northwest. The enrollment expands the utilities’ ability to incorporate additional renewable energy while continuing to meet the energy needs of their customers, reliably and cost effectively.  Furthermore, the inclusion of these new participants, allows the market to continue providing both economic and reliability through the real-time transfer of energy.

The WEIM employs advanced technology to locate and distribute the least cost energy to its participants, while improving dependability and giving considerable environmental advantages through the reduction of renewable energy curtailments during intervals of excess supply. Reducing curtailments leads to diminished greenhouse gas emissions, since the renewable energy, instead of going idle, can be utilized by other market members and may replace electricity produced using fossil fuels.

Amidst the backdrop of utilities joining the WEIM, the California grid operator is working to build on its progress through the expansion of an Extended Day-Ahead Market, where the bulk of energy transactions occur for members. As it stands, the stakeholder initiative process, which began in January, has established three working groups each dedicated to a market element that is instrumental in developing a plan that will meet the needs of the ISO’s partners in the West.

Avista Utilities serve more than 400,000 electric consumers in Washington and Idaho, whilst Tacoma Power, a publicly maintained utility serving nearly 200,000 electric customers in the Tacoma, Washington area. Bonneville Power Administration and Tucson Electric Power are set to become active participants of the market this year. With this, the market will have 19 members serving almost 77 percent of the electricity demand in the Western U.S.