A system includes a roof deck having a slope of 0.25 inch to 3 inches per foot and a roofing membrane is composed of a first material, and at least one photovoltaic module installed on the roof deck. The photovoltaic module includes at least one solar cell, an encapsulant, a frontsheet, and a backsheet. The backsheet includes a head flap located at a first end of the backsheet, and a bottom flap located at a second end of the backsheet. The backsheet is composed of the first material. At least a first portion of the head flap is attached to the roofing membrane, and at least a second portion of the bottom flap is attached to the roofing membrane.