Also known as photovoltaic (PV) cells, solar cells are the heart of a solar panel. . At the heart are photovoltaic (PV) cells that convert sunlight into electricity, supported by protective and structural layers that ensure it's delivered safely and reliably. The typical construction follows a specific order from top to bottom: protective glass cover, encapsulation film, photovoltaic cells, back encapsulation layer, protective backsheet or. . Solar panels are not a single functional element, but modules composed of multiple structural units. Each component plays a distinct role in optical protection, electrical energy conversion, mechanical support, and electrical connection. They are an increasingly popular and affordable source of renewable energy that continues to grow in relevance throughout the United States. Solar panels are composed. . From the outside, a solar panel looks like a simple sheet of glass in a metal frame.