The ISO/RTOs, with oversight by FERC and NERC, monitor their systems’ capac. In some areas, independent system operators/regional transmission operators (ISO/RTOs) are responsible for operating the transmission system reliably, including constantly dispatching power to balance demand with supply and monitoring the power flows over transmission lines owned by other public or private entities. The National Institute of Standards and Technology also is involved in developing standards for the grid. As part of its new authority, FERC has in turn granted the North American Electric Reliability Corporation (NERC)-a private organization created by the utility industry in 1968 to advise on reliability-the authority to develop and enforce reliability standards. The Energy Policy Act of 2005 expanded FERC’s mandate, giving it the authority to impose mandatory reliability standards on the bulk transmission system and to impose penalties on entities that manipulate electricity markets. Source: Courtesy of NETL Modern Grid Team. The Federal Energy Regulatory Commission (FERC) has long had the authority to regulate financial aspects of the transmission of electricity in inter-įIGURE 9.1 The current T&D system comprises two distinct but connected systems: transmission and distribution. For example, independent power producers (IPPs) may sell power to distribution utilities, or even directly to end users, using the transmission system as a common carrier (as shown in Figure 9.2). In deregulated areas, generation, transmission, and distribution may be handled by different entities. In the past, this was the dominant model, but deregulation in some states has transformed the industry. These fully integrated utilities own generating plants as well as the T&D systems that deliver the power to their customers. Federal, state, and municipal governments and customer-owned cooperatives all own parts of these systems, but approximately 80 percent of power transactions occur on lines owned by investor-owned regulated utilities (IOUs). T&D system includes a wide variety of organizational structures, technologies, economic drivers, and forms of regulatory oversight. In contrast to the transmission system, the distribution system usually is radial, meaning that there is only one path from the distribution substation to a given consumer. The power is then delivered to 131 million customers via the distribution system. The distribution system contains millions of miles of lower-voltage electrical conductors that receive power from the grid at distribution substations.
Power world simulator and wecc approved model solar generator#
The transmission system is configured as a network, meaning that power has multiple paths to follow from the generator to the distribution substation. The high-voltage transmission system (or grid) transmits electric power from generation plants through 163,000 miles of high-voltage (230 kilovolts up to 765 kV) electrical conductors and more than 15,000 transmission substations. T&D involves two distinct but connected systems (as shown in Figure 9.1): The Current Transmission and Distribution System The focus is on the technologies involved-their potential performance, costs, and impacts-and potential barriers to such a deployment in the United States over the next several decades. This chapter reviews the status of current T&D systems and discusses the potential for modernizing them (thus creating the “modern grid”). This massive system delivers power from the nearly 3000 power plants in the United States to virtually every building and facility in the nation. T&D system has been called the world’s largest machine and part of the greatest engineering achievement of the 20th century (NAE, 2003). Modernization of electric T&D systems could alleviate all of these concerns. In addition, distribution systems often are incompatible with demand-side options that might otherwise be economical. Moreover, effective and significant utilization of intermittent renewable generation located away from major load centers cannot be accomplished without significant additions to the transmission system. Recent concerns about T&D systems have stemmed from inadequate investment to meet growing demand, the limited ability of those systems to accommodate renewable-energy sources that generate electricity intermittently, and vulnerability to major blackouts involving cascading failures. Modern society depends on reliable and economic delivery of electricity. Growing loads and aging equipment are stressing the system and increasing the risk of widespread blackouts. Electricity Transmission and DistributionĮlectric power transmission and distribution (T&D) in the United States, the vital link between generating stations and customers, is in urgent need of expansion and upgrading.