Solar panels contain photovoltaic cells wired together in serial or parallel, topped with protective glass or plastic, and backed with an aluminum or other base. Photovoltaic cells are made of semiconductor material, often silicon.
When light hits the cells, the collision knocks electrons loose. The cell's electric field forces the electrons to flow in a current. Metal contacts on the top and bottom of each cell create a circuit that draws off the current.
The current can go either directly to a battery (like the one in a calculator), or to an inverter that converts DC to AC for home use. For battery storage (such as in an RV), a charge controller can slow the current, preventing the battery from overheating or overcharging.
Solar cells are usually warrantied for 25 years. Panels range from tiny (cellphone, garden accent lighting) to factory-roof panels.
To care for solar panels, regularly dust or wash them and remove debris, snow and bird droppings.
To work, panels must be pointed at the sun; angled panels work more efficiently. Panels can be laid flat, but consequently work less well.