Renewable energy is being increasingly utilized in electric power systems d
ue to environmental concerns and energy cost escalation associated with the
use of conventional energy sources. Photovoltaics and wind energy sources
can significantly offset costly fuel in small isolated systems and can also
have considerable impact on the system reliability. The utilization of ren
ewable energy in capacity planning requires realistic cost/reliability eval
uation models that can recognize the highly erratic nature of these energy
sources while maintaining the chronology and interdependence of the random
variables inherent in them. This paper presents an evaluation model and app
lies it to analyze optimum generation expansion of small isolated systems u
sing PV and wind energy sources.