A cogeneration solar system for a building located in Sabzevar (Iran) is investigated in this study. In this system, a combination of a solar evacuated tube collector field and an auxiliary natural gas burner drive a single effect absorption chiller. Solar energy is also used to produce consuming hot water. Hourly cooling demands of the building were calculated during April to September. In order to perform a more obvious assessment, important parameters such as COP and efficiencies were obtained based on the total cooling load, the total amount of absorbed solar energy and consumed natural gas, and the total produced hot water during April to September. Energetic, exergetic, and economic analyses were performed in order to find the most efficient generator temperature. Considering the results, the minimum consumption of natural gas happened at a generator temperature of 104 degrees C while the highest chiller exergy efficiency is observed at the generator temperature of 97 degrees C. Also by assuming the required gas fuel to supply the consuming hot water-which is produced by solar energy-as a saving parameter, the economic optimum generator temperature to drive the absorption chiller and to supply the consuming hot water is obtained at the generator temperature of 96 degrees C. (C) 2020 Elsevier Ltd. All rights reserved.