2009 Scenario Reliability Assessment - NERC

Scenario Reliability Self-AssessmentsTransmission ImpactsThe TEPPC study indicated which of the major paths in the Western Interconnection would faceincreased constraints with the addition of 15 percent renewable generation. The major paths thatwere studied are shown in Figure 2.Figure WECC-2 - LOCATION OF MAJOR WECC PATHS# Path Name36203178&79352349461536665811437TOT 3PATH CTOT 2ATOT 2BTOT 2CFOUR CORNERS 345/500 kVEAST OF COLORADO RIVER (E O R )WE S T OF COLORADO RIVER (WOR)MIDWA Y ‐ LOS BANOSNORTHWEST – CANADACOIPACIFIC DC INT E R TIE (PDC I)MONT ANA – NORTHWESTALBERTA – BRITISH COLUMBIAIDAHO – NORTHWESTTOT 4AGenerally the most heavily loaded paths or path elements, using a study metric of at least 20percent of time loaded at least 99 percent of path rating, were the following:TOT 2C (Southwest Utah to Nevada)Four Corners 345/500 kV transformerMontana-Northwest PathAlberta-British ColumbiaUsing a metric of at least 10 percent of the time loaded at least 99 percent of path rating the mostheavily loaded path added Northwest-Canada to the list of congested paths.These paths are used in transfers from the wind generation areas of Montana, Wyoming,Colorado, and British Columbia in the North and Northeast parts of the interconnection to themajor load centers along the Pacific Coast (Seattle to Southern California). Several other paths2009 Scenario Reliability Assessment Page 153