An AC module is a photovoltaic module which has a small AC inverter mounted onto its back side which produces AC power with no external DC connector. AC modules are defined by Underwriters Laboratories as the smallest and most complete system for harvesting solar energy.[1]
Underwriters Laboratories (2005), UL 1741 Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources, UL 1741, Northbrook, IL, pp. 17