This paper presents the development and application of a dynamic mathematical simulation model of a solar domestic hot water (DHW) production system designed for a 4-star hotel located in Fez, Morocco. The hotel consists of 60 rooms and accommodates approximately 120 guests, resulting in a high and continuous demand for hot water. The main objective of the study is to evaluate the energetic performance of the solar thermal system and to assess its capability to meet daily and annual DHW requirements under local climatic conditions. The investigated system includes a flat-plate solar collector field, two hot water storage tanks, an external heat exchanger, and an auxiliary heating unit to ensure service continuity during periods of low solar availability. The proposed model enables fully dynamic simulation of system operation, taking into account local meteorological data, collector orientation and tilt angle, thermal characteristics of system components, and realistic DHW consumption profiles representative of a 4-star hotel. Simulation results obtained for a typical meteorological year show that the solar system supplies, on average, approximately 58% of the annual DHW demand, with solar coverage reaching 70–75% during summer months. In addition, an average reduction of nearly 48% in auxiliary energy consumption is achieved, with peak reductions reaching up to 60% during summer months, together with a significant improvement in overall system efficiency and satisfactory thermal stability of the storage tanks, despite demand peaks associated with hotel occupancy. The originality of this work lies in the adaptation of the developed dynamic model to a high-demand 4-star hotel application in Fez, representative of the Moroccan tourism sector, and in the detailed assessment of the impact of local climatic conditions on solar thermal system performance. The proposed approach is intended to serve as a decision-support tool for the design and optimization of solar thermal installations in mediumand large-scale hotel buildings.
Lahdya et al. (Fri,) studied this question.