Beyond smart grid technologies, modernizing the nation’s electric grid must address a host of evolving system development issues. With a growing array of diverse centralized, distributed and renewable generation, power system managers are increasingly addressing complex interconnection issues and resource-balancing challenges—with a constant eye on reliability and long-term security.

A critical factor affecting transmission system development is the assumed location and size of generating units. The representation of generation in a planning model depends both on what generation is included and the output of these generators. The matter as to what generation is included in the model depends on the treatment of the generation in the generation queue. The output of the generators is set by the assumed generation dispatch.

With transmission plans being developed five and ten years into the future the treatment of the generation queue is an important variable. There are at least three general types of generation dispatch used in transmission planning—economic dispatch, stressed dispatch, and flat dispatch. Each will result in a different pattern of generation and subsequent transmission loadings. These different transmission loadings can affect what transmission improvements are needed.

KEMA’s Jeff Palermo had his paper published at the CIGRE Operation and Development of Power Systems in the New Context International symposium held in Guilin, China October 28 – 30, 209. His paper discussed the generator queue and dispatch practices of five systems: The PJM Interconnection; Dominion Virginia Power, The California ISO; The Electric Reliability Council of Texas; and The Alberta Electric System Operator.

A portion of the PJM transmission system is used to demonstrate the potential impact of different assumptions regarding generation dispatch. The pros and cons of different approaches are also discussed

The full paper is available for download at: http://www.kemautilityfuture.com/wp-content/uploads/2009/10/Generation-dispatch-in-transmission-planning.pdf