Hybrid photovoltaic/thermal (PV/T) solar systems can simultaneously provide electricity and heat, achieving a higher conversion rate of the absorbed solar radiation than standard PV modules. This paper focuses on photovoltaic thermal water systems, which feature a photovoltaic module placed in thermal contact with a water- based solar thermal collector. When properly designed, PV/T systems can extract heat from PV modules, heating water or air to reduce the operating temperature of the PV modules and keep the electrical efficiency at a sufficient level.PVT/water systems are considered the most efficient way of preheating water over the course of a whole year. The maximum of heat gain from the PVT systems where obtained in January in summer. The PVT collectors have expected yield of 1367.36Kwh/(m2year) of heat and 323.89kWh/(m2year) of electricity respectively given the Addis Ababa environment, with expected panel cost between 12.56 Birr(0.45€)/wp and 25.12 Birr (0.90€)/wp. Economical evaluation based on energy costs was conducted, which estimated the payback time would be 13 up to 14 years for Mono-crystalline silicon PVT.