Discussion of WECC Paths TOT 1A Path 30

Discussion of WECC PathsTOT 1A - Path 30Figure 1: Path 30 DefinitionHistorical CongestionThe 2009, 2008, and 2007 Transmission Path Utilization Studies include analysis on Path 30.Path 30 is historically congested based on flow metrics from the 2007 Path Utilization Study.There was at least one season analyzed in the 2007 Study period where Path 30 seasonalloading exceeding 75 percent of operating transfer capacity 50 percent of the time or more. Thisqualified Path 30 as one of the most heavily utilized paths in the Interconnection according tothe 2007 Study. The 2008 Study reported Path 30 operating at or above U75 for 19 percent ofthe study year. However, it was not named as one of the Western Interconnection’s mostheavily utilized paths in that study. The 2009 Study cited decreased flow from 2008 levels asPath 30 operated at U75 for eight percent of the year. Path 30 had 80 MW of firm ATC availablefor 95 percent of the study year, and did not make the final list as one of the most heavilyutilized paths in the 2009 Study. Actual flow data can be found in the duration plot in flow inrecent years has decreased relative to 2000 levels. Although informative, the plot does notnecessarily reflect the metrics that support the path as historically congested.Figure 2. As evident in the figure, flow in recent years has decreased relative to 2000 levels.Although informative, the plot does not necessarily reflect the metrics that support the path ashistorically congested.Deleted: %Deleted: %Deleted: %Deleted: 8%Deleted: %Deleted: Figure 2Page 2 of 4

Figure 2: Path 30 Actual Flow Duration PlotDiscussion of WECC PathsTOT 1A - Path 30Project DevelopmentStakeholders did not identify any specific potential projects that may have a direct impact onPath 30 flows.Future Congestion AnalysisThe forward looking congestion analysis draws upon study case results from production costmodel runs based on 2019 and 2020 datasets. This work was done as a part of the 2010 StudyProgram.Expected FuturePath 30 was not heavily utilized or congested in the expected future case. TOT 1A operated atU75 for only 1.38 percent of the year, and at U90 for only 0.23 percent of the year. The durationplot in Figure 3 shows this relatively low utilization. The chronological plot in the same figureshows the seasonality of the flows. It is worth noting that the 2019 and 2020 datasets assumedan increase in Path 30 capacity from 650 MW to 800 MW. Without this increase the utilization ofthe path could have been higher in the expected future scenario.Deleted: %Deleted: %Page 3 of 4