Installing LED based lighting system is a good choice to reduce the energy consumption in houses and small offices. They are extremely efficient, using up to 80% lesser energy than an equivalent incandescent lamp, radiate much less heat, have longer lives and require lesser maintenance. This paper evaluates a new installed DC direct-coupled photovoltaic system that enables the use of DC power directly for LED-based office lighting. A conventional DC-AC solar energy system is also installed on the same building and will be monitored for comparison purposes. The principle goal of the project is to examine the performance of the installed DC system, both economically and functionally in order to practically consider them for selected applications.