U.S. state has its own unique regulations and standards that solar design engineers need to consider, particularly when seeking a Professional Engineer (PE) stamping to ensure structural safety, electrical code compliance, and the adherence to local building codes, it generally requires a licensed professional engineer or PE engineer to review and stamp solar engineering documents related to a project. Stamping is typically required for projects requiring permits, or if the project exceeds a certain size, and includes structural plans for mounting systems, electrical wiring diagrams, and site layout plans. Stamping may also be mandatory for projects requiring permits.