2023 ASEE Annual Conference & Exposition

Solar photovoltaics (PV) has emerged as a major renewable energy source. The tremendous growth of the solar PV industry has created a demand for skilled engineers to support the future green energy infrastructure. To prepare competent graduates, laboratory aided practical engineering education is of high importance. With this goal, a rooftop solar photovoltaics laboratory has been designed and developed for a solar power course. The laboratory facility is equipped with twelve 100 watts solar modules with a total installed capacity of 1.2 kilowatts. Tilt angles of the modules can be altered within a range of 30 degrees. Unlike conventional PV systems, the modules in this facility are not directly interconnected into a fixed array configuration. By programming through a graphical user interface (GUI), the array configuration can be changed as required for different experiments. The output cables from the modules are connected to a matrix of electromechanical relays that facilitate programmable rewiring of the modules. A GUI program has been developed which displays the system layout graphically with each component status represented in real-time. The GUI allows to visually interact with the PV arrays and perform various electrical measurements. After connecting the modules in a specific array configuration through the GUI, the output of the relay matrix is connected to a programmable electronic load. The lab computer communicates with a Raspberry Pi (RPi) which controls the relays and the electronic loads to perform current-voltage (I-V) and power-voltage (P-V) characterizations. In addition to flexible variable array configuration, another innovative and advanced feature of this lab facility is the capacity to implement maximum power point tracking (MPPT) algorithms. A set of six lab exercises were developed which include surveying and sketching the PV system layout, I-V and P-V characterization for series and parallel connected panels, analyzing daily power graphs for energy calculations, implementation of a hill-climbing MPPT algorithm, and studying the effect of different tilt angles on solar power production. This innovative, easy-to-use laboratory setup is expected to bolster the engineering concepts learned in the classroom, provide an enhanced learning experience to the students, and improve their competency level. Hardware and software design, details of the lab exercises, and future improvement plans are presented.