Off-design performance of power plants: an integrated gasification combined-cycle example.

Fossil-fueled power plants typically operate below their design capacities for a large fraction of their service life. In the United States, increased fuel and capital costs attributable to this off-design operation are considerable. This article describes the reasons for off-design operation and its importance in designing and selecting new power plants. Recent studies of coal gasification combined-cycle power plants show how computer simulations of off-design performance can aid in the design process, and they suggest that such simulations can be useful in reducing the cost of building and operating new power plants.