Solar collectors are an environmentally friendly solution for the production of hot water, but can also contribute to the heating of rooms. They can be used in combination with any other method of heat production used in case of low sunlight (wood heating, heat pump, oil or gas boiler). They make it possible to solve the problem of the high cost of electricity and especially of the regular load shedding that the population meets. To solve the problem related to the production of hot water, we sized a solar water heater capable of meeting the needs of thirteen people; with a backup system to compensate for the drop in temperature during the period when we have low sunlight.