<p>Integrating solar heating for industrial processes (SHIP) requiring hot water can be economical, depending on the type of processes and the existing energy sources. Industrial processes vary in temperature requirements, the amount of heat needed and the timing of heat demand. Therefore, designing a SHIP system requires detailed analysis and optimization to maximize efficiency. This study presents a method combining TRNSYS simulation and GenOpt optimization for SHIP integration. The optimization includes the method of constraint function that would result in a balanced size of the collector area and thermal energy storage, which would reduce the risk of overheating the solar collectors. To demonstrate the optimization, a case study of a soft drinks bottling factory was considered, with typical processes demanding up to 245 m3/day of hot water. The simulation and optimization results of the case study showed that integrating SHIP could achieve life cycle cost savings of over 60%, compared to that of a diesel boiler system. The optimal values for the collector area, storage volume, and mass flow rate were 3472 m2, 150 m3, and 37,500 kg/h, respectively. The optimal collector area and storage volume per unit volume of daily hot water demand were approximately 14 m2/m3 and 0.6 m3/m3. The constraint function implemented in the optimization kept the collector temperature below 95 °C, minimizing the risk of overheating.</p>