The Fuel Supply Plan referred to in 80.1450(b)(3) refers to fuel used at a renewable fuel production facility to generate process energy. "Source" means the name of the supplier of that fuel. Since 80.1450(b)(1)(iv) asks for the locations from which the process energy fuel types were produced or extracted the name and address of the supplier would not satisfy this requirement; we are asking for the location where the biogas is produced. We intend to clarify this through our upcoming technical amendment to the regulations.