What hot water supply system is better for a small hotel with 40 rooms?

The solar hot water system heats the water to the required temperature by absorbing the energy of free sunlight, and the hot water is stored in the heat preservation water tank, which reduces the heat loss and ensures that the hotel room can supply hot water 24 hours a day and can be heated immediately. When the weather is clear, priority is given to using free solar energy to make hot water. Only when it rains and snows for a long time, it is necessary to start the auxiliary heating system. Therefore, the comprehensive utilization of solar hot water system and auxiliary heating system is cheaper, more economical and safer than simply using electric hot water and natural gas to heat water.