FIGURE 9.2 Key players in the T&D system. Power is produced by regulated investor-owned utilities (IOUs), which own the majority of the T&D systems, and in some areas by independent power producers (IPPs). IOUs typically provide electricity to end users through their own distribution systems, while IPPs sell to a utility or purchase transmission services to deliver electric power directly to an end user. There are also utilities that are federally or locally owned, such as municipal and rural co-ops. Most of these utilities own generating plants as well as T&D lines.
Source: Courtesy of NETL Modern Grid Team.
ities and conduct the wholesale market to clear short-term transactions.2 There are nine ISO/RTOs in North America, as shown in Figure 9.3. Seven of the nine come