Initially it is more expensive to buy a water solar heating system than a conventional gas heater. However, the water solar heating system uses the sun's free energy while the conventional gas heater uses fossil gas which is not free. The accumulated expense that involves the purchase month by month of gas comes soon equal to the expense made in the purchase of the water solar heating system. It is estimated that the average recovery period of the money invested in the water solar heating system is between 1 and 3 years.
Working Principle:
