<p>This paper aimed to examine the possibility of supplying warm water for a 90-student-primary school using solar energy. The used solar water-heater belongs to Solar Polar Company. The RETScreen4 software was used for economic analysis and determining the time of capital return. Some different scenarios were used for analysis indicating the increase of the time of capital interest by reduction of the inflammation rate. In addition, if government pay for the 50% of expenditure, the capital return will be obtained 2.4 years sooner.</p>