The project is to Design and Develop an OFF-GRID solar photovoltaic System using DC-DC Topologies for BIUST classrooms light loads (lighting, projector, and computer). Narrowing this topic, focus is on harvesting solar energy using photovoltaic cells then boost the power using a DC-DC boost converter. This project consists of different subsystems, which are combined to have the solar system for classrooms light loads. These are Photovoltaic Solar Array, Maximum Power Point Tracking (MPPT), DC-DC boost converter and battery bank stores energy to be used when the sunrays are not efficient to supply the load. Lastly a DC-to-AC inverter is designed. The system is design is based on performed calculation to size each component to keep the system efficiency high. According to simulation of different DC-DC converters using Simulink, boost was the best converter to use looking at the output characteristics desired. Results from Proteus software simulation of the final circuit correspond with expectation from literature review. Furthermore, PVsyst software has been used to do the mathematical analysis of the designed model showing an estimated payback period of 2.6years whereas the output power for PVsyst model is 11.9 kW which the system produces given the design parameters calculated.