The Engineering Building of Baskent University had a major energy efficiency renovation in the summer of 2010, which made it technically more feasible to utilize solar energy systems. In this respect a techno-economic analysis was made to implement a 15 kW solar PV system on the south facade of the building. This system has 15 kW maximum electric power capacity and will involve novel PVTC modules, which stand for power, thermal and cold, in other words solar tri-generation. Calculations show that the overall exergy efficiency reaches about 50% and the overall COP reaches almost one at the cooling mode, because the indoor heat is also harnessed to produce domestic hot water. This paper describes the fundamentals of the system and explains the carbon emissions reduction potential in terms of energy and exergy efficiency over simple PV modules with the same power capacity.