BPA, Western Utilities Propose New Plan For Major Transmission Line

The Bonneville Power Administration (BPA), Idaho Power and PacifiCorp have reached a non-binding agreement that clarifies and updates roles and responsibilities for the Boardman to Hemingway (B2H) transmission line, a 500-kilovolt, 290-mile transmission line that would deliver 1,000 megawatts of power in each direction between the Pacific Northwest and Mountain west.

Under the agreement, Idaho Power and PacifiCorp, both of which are investor-owned utilities, will jointly own the B2H transmission line, with PacifiCorp owning 55% and Idaho Power owning 45%.

Idaho Power will acquire an ownership interest in PacifiCorp transmission lines and other equipment between eastern Idaho and the Four Corners Substation in northwest New Mexico.

BPA will transfer its ownership interest in B2H to Idaho Power and will not participate in construction or have any ownership interest in the transmission line project.

Facilities currently used by PacifiCorp to serve BPA’s customers in and around southeast Idaho will be transferred to Idaho Power. 

BPA will acquire transmission service over Idaho Power’s transmission system, including the newly constructed B2H, to reliably and cost-effectively serve public utility customers in Idaho, Wyoming and Montana.

Under the agreement, PacifiCorp will acquire Idaho Power transmission assets across southern Idaho that, combined with its majority stake in Boardman-Hemingway, will increase its contiguous power transfer capability between its Western and Eastern systems, and will acquire additional transmission service from BPA to enable it to serve its growing customer base in central Oregon.

With the non-binding term sheet developed, the three organizations will move into a negotiation phase to finalize the agreements and seek regulatory approval. 

BPA issued a letter to its regional stakeholders and customers that outlines the proposal, describes the background and explains the process for engaging with BPA on this topic. The letter is available here.

The term sheet and background information about B2H is available at the project website.   

B2H is expected to come online in 2026.