Improving the Operation of Solar Water Heating Systems in Green Buildings via Optimized Control Strategies

Solar water heating (SWH) systems are well known and effective structures that transfer solar energy into thermal energy with hot water as the storage. The efficiency of an SWH system is mainly based on well-designed solar collectors and proper operation mechanisms. Although the most existing literature has focused on the efficiency enhancement of solar collectors, limited studies are devoted to improve the operating mechanism. As such, this paper studies the control mechanisms of the SWH system with a purpose so as to help the building manager to achieve targeted energy management goals. In particular, three control approaches are presented for improving the operational efficiency of the SWH system by controlling auxiliary heaters, such as heat pumps, electric heaters, and circulation pumps. The proposed approaches are developed based on different requirements of information such as the hot water demand, weather, and electricity price. Moreover, three various energy management objectives are studied with considering different scenarios in terms of real weather pattern and hot water demand of a commercial building. The results validate that the proposed approaches can improve the operation of the SWH system according to various operation objectives.