This article provides a comprehensive overview of the four main types of Solar Photovoltaic Systems-On-Grid, Off-Grid, Hybrid, and Microgrid. From photovoltaic cells to solar thermal systems, these technologies vary in their working principles and uses. As you read through, please also open the links within each paragraph to get more information about each. Technology overview: photovoltaics, CSP, and biomass, plus complementary applications such as indirect wind power and passive solar heating. CSP uses mirrors. Energy from the sun reaches us in several practical forms.