Usable hydro capacity and electric utility production simulation and reliability calculations

The two most common ways of modeling the energy limits of hydro plants in production simulation programs are compared. The first method dispatches hydro plants against the load duration curve prior to convolving any thermal-unit-outage random variables with the load. This method is often referred to as peakshaving. The second method dispatches hydro plants against the equivalent load duration curve (ELDC) after convolution of some or all thermal-outage random variables. Test results indicate that the peakshaving approach is more appropriate in terms of the implied usability of the hydro capacity