ABSTRACT
Intermittent solar and wind energy sources stress the £exibility limits of fossil fuel generation sources to the point where some exhibit severe inef-ˆciencies. Because the utilization of intermittent energy sources is generally mandated by renewable portfolio standards (RPS), system operators must dispatch fossil fuel units to meet total load net of renewable generation, known as net load. Flexible generation sources such as stored energy and natural gas power plants are able to balance the intermittent and volatile generation outputs of wind and solar energy, in contrast to coal facilities that are made more inefˆcient by irregular operation. When coal facilities are
CONTENTS
Introduction ........................................................................................................... 17 Wind, Gas, and Coal Integration ........................................................................ 18 Impacts of Cycling ................................................................................................ 21 PSCO Case Studies ................................................................................................ 29
Data and Methodologies ................................................................................. 29 July 2, 2008, Wind Event ..................................................................................30
