Analysis and Optimization Design of a Solar Water Heating System Based on Life Cycle Cost Using a Genetic Algorithm

This paper presents an optimization method to design a solar water heating (SWH) system based on life cycle cost (LCC). A genetic algorithm is employed to optimize its configuration and sizing as the optimization technique. To ensure that the optimal solution obtained from the proposed method is a practical design, three constraint conditions, including the energy balance, solar fraction, and available space to install solar collectors, have been set. In addition, the real devices available in the marketplace are considered in the optimization process that searches for optimal configuration and sizing, which is represented by the type and number of each component. By using the proposed method, a SWH system in an office building, South Korea has been designed and optimized. It is observed that a low solar fraction does not always present a decrease in the LCC. A trade-off between the equipment cost and the energy cost results in an optimal design of the SWH system that yields the minimum LCC.