In the communication sector, in order to provide broadband internet and fixed telephone services to customers, systems called external active access devices are installed inside the building. These devices, which are usually installed in buildings in the city centers, are supplied by energy from city grid. In this study, economic analysis of HUAWEI MA5622 external active access device have been explored which is installed in 185 buildings in Karabuk province is provided by grid connected solar energy system. Karabuk province has been taken as a role model for the other regional applications that would be applied later, and after this stage it will be called as "pilot province". First of all, 300 Wp installed solar power system was designed to meet the greatest amount of energy needs of system and to meet the missing energy requirements from grid. In this way, minimum material cost and depreciation period at low installed power were calculated. Afterwards, beyond the entire power demand of the system was met, the excess power produced was planned to be sold to rid and installed power was increased. In this way, 5 different installed power system design in 600Wp, 1.5kWp, 3kWp, 5kWp, 10kWp was also made by calculating depreciation period for each system designed. The design and simulations of solar energy systems were realized by program named as PVSYST. According to the data obtained from the simulation results, the depreciation periods of the systems designed with 300Wp, 600Wp, 1.5Wp, 3kWp, 5kWp, 10kWp installed power are calculated respectively 37.8 years, 22.1 years, 16.3 years, 13.1 years, 12.2 and 9.9 years. As a result, it has been seen that depreciation period decreases as the installed power increases and the most economical system design is found to be 10kWp installed power system.