The Western United States power grid is increasingly experiencing south-to-north electricity flow patterns, reversing long-standing historical trends in a shift that may demand significant system changes and more precise generation forecasting, according to speakers at the Market Seams workshop hosted Tuesday by the California Independent System Operator and Southwest Power Pool. The changing flow patterns are raising concerns about whether existing grid protection systems remain adequate as renewable energy deployment accelerates faster than transmission infrastructure can be built to support it.
Chris Sanford, a system dispatcher with Bonneville Power Administration, expressed worry during a workshop Q&A that current automated grid protections don't account for the growth of northbound power flows. The Western Interconnection can divide along its north-south boundary to protect grid stability under certain conditions through an automated response called WECC-1 RAS, or Remedial Action Scheme. But Sanford said that if a triple line failure occurred on the California-Oregon Intertie with 3,600 MW flowing south-to-north, "I don't think California is prepared to deal with the loss of 3,600 MW of load," and responding to a 3,600 MW generation loss in the Pacific Northwest would also prove difficult. "We still haven't solved that problem. Honestly, I don't even think we're looking at it," he said.
Workshop moderator Raja Thappetaobula, director of RC West Operations at CAISO, acknowledged Sanford's concern and said a "major study" into whether the WECC-1 RAS needs revision is required. RC West has begun working with the Western Electricity Coordinating Council on the issue, finalizing key study scenarios with plans to conduct the studies next year, according to Thappetaobula. Daniel Koppes, director of main grid operations with PacifiCorp, said discovering new stability limits as power flows and configurations change is "what I lose sleep about at night," adding that the system's rapid transformation makes it difficult to identify problems ahead of time despite efforts to update tools and models.
The speed mismatch between different grid changes is creating the challenge. "You can build renewables way faster than you can build transmission, and you can decommission coal plants way faster than you can build transmission," Koppes explained during the workshop. Several speakers emphasized the importance of data sharing to address transmission constraints, with Yasser Bahbaz, senior director of operations support with SPP, urging energy merchants and marketers to update their offers as far ahead as possible since grid operators rely on those projections to assess economics and future market conditions. Sanman Rokade, manager of transmission operations engineering at Portland General Electric, raised concerns about ensuring data consistency across organizational boundaries so different entities examine the same constraints using identical inputs.
The Western grid's evolution reflects a broader transformation as solar and other renewable generation in the Southwest increasingly sends power northward, while traditional patterns saw hydroelectric and other generation flowing south. Bahbaz noted that coordination efforts like Western Interconnection Loading Relief are moving in the right direction, requiring only "coordination, continued conversations" to address seams issues. The fundamental question remains whether safety systems designed for one flow pattern can adequately protect a grid operating in reverse—a question that grid operators are just beginning to study systematically as the energy transition accelerates beyond the pace of infrastructure adaptation.