Short term reliability and cost of operation for an autonomous energy system

The authors describe an algorithm for determining the reliability and cost of operation of an autonomous energy system consisting of diesel units and wind generators over a period of T hours. The simulation period is divided into intervals of t minutes duration. Given the characteristics of the diesel and wind generators, the hourly loads, and the statistics of wind velocity, the algorithm finds the cost of operation and reliability of the system over each interval and the whole period T for each alternative commitment schedule. The proposed algorithm is a module of an overall scheme used for comparing alternative commitment schedules in order to find the optimal one, i.e. the one which provides the minimum cost under a given reliability. The random nature of wind velocity and load demand is taken into consideration by utilizing stochastic models for the diesel and wind generator operation. Results obtained by the application of the algorithm to an autonomous energy system for a medium-size Greek island are reported