摘要
Active exploitation of solar energy is achieved in systems that absorb this energy through flat collectors. Hot water can be used for space heating, when its temperature is high, but it is used largely for DHW （domestic hot water） needs. Now days, this technology has resulted as the most viable for exploitation of solar energy, and various countries such as Israel, Turkey, and Greece provide hot water for residential and service sectors using systems of solar panels. In this proceeding we are writing about the dimension of the solar panels surface based to the net present value in Hotels of Albania.
