Wholesale Market Operations
Most energy (over 95 percent) consumed within the ERCOT power region is purchased through the bilateral market, so called because it involves contracts between power generating companies and load serving entities (LSEs), which can be retail electric providers, municipally owned utilities and cooperatives. The scheduling of power purchased through these agreements is reported to ERCOT through Qualified Scheduling Entities (QSEs). The QSEs provide the schedules of all power loads and generation that they are representing in the ERCOT power region. QSEs may represent generators, power marketers (those who buy and sell energy in the bilateral market) and/or load serving entities; all generators and LSEs must be represented by a QSE.
These QSEs are required to inform ERCOT of the private contractual agreements in the bilateral market for each 15-minute period of the day, so that ERCOT can ensure that the supply and demand for energy are sufficiently balanced.
Source: The Electricity Reliability Council of Texas.