A unitized photovoltaic assembly is disclosed. A unitized photovoltaic assembly consists of a unitary frame designed to retain a plurality of photovoltaic modules. The unitary frame is formed by orienting a plurality of rails in the lateral direction above and mounted to a plurality of struts oriented in the vertical direction. Once the unitary framed is formed, photovoltaic modules slide into slots running the length of the rails and are thus retained in the unitary frame. Also added to the unitary frame are a series of power conversion elements, retaining brackets, mounting brackets, and cleaning elements. The completed unitized photovoltaic assembly can be fabricated off-site, transported as a single unit and installed to a roof or other surface with the use of a specialized lifting frame, also disclosed. Additional unitized photovoltaic assemblies can be mechanically and electrically interconnected to form a complete photovoltaic system.