Transmission performance assessment

Transmission availability has become the significant indicator of overall transmission system operational health, due to increased utilization of the transmission system, growth of deregulated energy wholesale markets, and decreased investment in new transmission assets. The industry´ is increasingly dependent on flow based transactions which are not adequately assessed by traditional distribution load interruption metrics. While generation availability assessment has NERC´s GADS database, transmission facilities lack a similar repository. Regionalized transmission reliability jurisdictions and energy market operators in North America maintain separate reporting formats. Transmission availability assessment is limited by differences in reporting formats and underlying definitions. Recent availability trends reflect the increasing dependence upon existing assets to support expanding markets. This paper discusses the differences in transmission availability assessment and the need to increase between system comparability through collaborative development of definitions and data methodology