Three utilities, BPA, to partner on new transmission line

Three public utility districts in central Washington state are planning to join forces with BPA to fund a new transmission project. Under the pending plan, the Chelan, Douglas, and Grant County Public Utility Districts (PUD) and BPA will partner to finance and build the nine-mile, 230-kV north mid-Columbia joint transmission project.

The project was recommended in a technical report published by ColumbiaGrid in February 2010 as a way to enhance reliability in the area by reducing existing system constraints more efficiently than would single-utility projects.

“Douglas PUD and Grant PUD have single-utility projects that they need for their own load service,” Chad Bowman, Chelan PUD’s transmission and compliance director, told TransmissionHub on May 29. “Those projects, in and of themselves, make the congestion a little bit worse, but this joint project integrates the whole into a single plan of service that works very nicely for everyone.”

Two existing 230-kV lines between Rocky Reach and Columbia, Wash., become heavily loaded during the high-demand summer months and “have the potential to overload during certain system contingencies and show up in NERC studies as issues that need to be addressed,” Bowman said. “This new joint project adds basically a third line.”

The new line would also give the region additional capacity needed to accommodate growth, and would reduce the demands on BPA and Chelan PUD transmission lines that serve an aluminum smelter in Wenatchee, Wash., Bowman said.

Douglas PUD will design, build, own and operate the line, but all parties will help pay for and maintain it.

Under the proposal as it presently exists, BPA would cover approximately 42% of the estimated $14m price tag. Chelan PUD would pay approximately 24%, and Douglas and Grant PUDs about 17% each. In return, Chelan PUD would get more than 41% of the line’s capacity, Douglas would receive nearly 30%, and Grant 29%.

“We have an agreement at the staff level that still requires the approval of the boards of commissioners for Chelan and Grant PUDs to move forward,” Bowman said. Douglas County PUD commissioners approved the joint project on May 21. BPA will also decide on the project in the coming weeks.

Bowman said the project makes the most of the synergy between the PUDs, as well as economies of scale.

“It really performs very well; much better than if we were to go it alone, by ourselves, and build something,” he said. “If Chelan were to do a project that performed the same way this joint project does, it would be much, much more expensive than [our share of] the joint project.”

If all parties agree, construction could begin in 2014.