A solar panel including a photovoltaic material layer; a backing panel; and an adhesive layer disposed between and adhering together the photovoltaic material layer and the backing panel, in which the adhesive layer comprises an adhesive composition, the adhesive composition comprising a low MVTR polymer or copolymer and a silane-modified polymer or copolymer. In another embodiment, the solar panel includes module wire openings which are filled by an adhesive composition comprising a low MVTR polymer or copolymer and a silane-modified polymer or copolymer. A method of making the solar panel is provided.