Abstract
An efficient approximate method for large scale optimal unit sizing of energy supply systems is proposed based on the following two intuitive hypotheses : (a) optimal equipment capacities exist between minimum and maximum ones obtained by solving partial problems, and (b) for a certain sampling time, if on-off status of equipment for the minimum capacity is equal to one for the maximum capacity, on-off status of equipment for the optimal capacity is equal to those states. By solving small scale problems plural times based on these hypotheses, equipment capacities and utility contract demands as well as systems' operational strategies are efficiently determined to minimize the annual total cost and to satisfy energy demand requirements. Numerical studies on gas engine cogeneration systems installed in a hotel are carried out to ascertain the validity and the effectiveness of the proposed method.
