This book presents a case study on a new approach for the optimum design of rooftop, grid-connected photovoltaic-system installation. The study includes two scenarios using different brands of commercially available PV modules and inverters. It investigates and compares several different rooftop grid-connected PV-system configurations taking into account PV modules and inverter specifications. The book also discusses the detailed dynamic MATLAB/Simulink model of the proposed rooftop grid-connected PV system, and uses this model to estimate the energy production capabilities, cost of energy (COE), simple payback time (SPBT) and greenhouse gas (GHG) emissions for each configuration. The book then presents a comprehensive small signal MATLAB/Simulink model for the DC-DC converter operated under continuous conduction mode (CCM). First, the buck converter is modeled using state-space average model and dynamic equations, depicting the converter, are derived. Then a detailed MATLAB/Simulink model utilizing SimElectronics® Toolbox is developed. Lastly, the robustness of the converter model is verified against input voltage variations and step load changes.