BPA plans upgrades for Pacific DC Intertie

The Bonneville Power Administration (BPA) is proposing $428m in upgrades to the Pacific DC Intertie (PDCI) between the Pacific Northwest and southern California. 

If approved by BPA’s capital allocation board, the upgrades will modernize the facility, which was energized in 1970, and increase its capacity while simultaneously reducing operating costs.

BPA is proposing to upgrade two major portions of the 42-year-old intertie, which is one of the world’s longest and highest capacity transmission lines. 

BPA plans to replace the aging Celilo 4 converter terminal on the Columbia River near The Dalles, Ore., with a new two-converter terminal. 

“Some of the equipment at our Celilo Substation is so old, finding replacement parts has become a challenge,” BPA’s senior vice president for transmission services, Brian Silverstein, said in a statement. So challenging, in fact, that BPA has occasionally turned to eBay to locate the equipment it needed. 

The utility will also upgrade its portion of the transmission line, which runs from Celilo to a trading hub north of the California border. 

The proposed upgrades are “contingent on some form of environmental review” under the National Environmental Policy Act (NEPA), a BPA spokesperson told TransmissionHub on Feb. 23. Once that review is completed, BPA will decide whether to proceed with the upgrades.

The upgrades would increase capacity from 3,100 MW to 3,220 MW immediately with the opportunity to further increase capacity to 3,800 MW. The upgrades would also help BPA avoid outages and strengthen the line against weather and other threats.

In addition to increased capacity, the changes would yield other benefits. 

Operating and maintenance costs would be reduced by an estimated 30%, according to a presentation to a BPA transmission customer forum in early February. The new facilities would use equipment from a single manufacturer, making repair/replacement more efficient and economical. The reduced amount of equipment will improve reliability, availability and maintainability, as well as allow a substantial reduction in spare parts inventory.

Further, the utility said, simpler configuration facilitates remote operation, dynamic scheduling and capacity tags.

The upgrades will be paid for exclusively by the users of the PDCI, which enables BPA to send hydropower to southern California, and import power from southern California to help meet peak demand.

The PDCI is connected exclusively to the Sylmar Converter Station in the San Fernando Valley north of Los Angeles, which is owned by five utility companies and managed by the Los Angeles Department of Water and Power. 

If a decision is made to move forward, the utility plans to identify a contractor by the end of this year. Construction could begin as early as 2015 and is currently expected to take approximately one year. 

Photo courtesy Bonneville Power Adminnistration.