Typically, when people talk about solar panels, they are referring to Photovoltaics.
Photovoltaics is a solar energy technology that uses unique properties of semiconductors to directly convert solar radiation into electricity (Source: Photovoltaic Systems, 2007, American Technical Publishers)
These systems, referred to as photovoltaic systems (commonly called PV systems), are comprised of PV cells, or solar cells, made up of crystalline silicon “chips” or “wafers”. These cells, when exposed to sunlight, generate small amounts of direct current electricity.
When these cells are put together and combined, they then become a solar module, generating a larger amount of direct current electricity together. This solar module is more commonly called a solar panel.
When these panels are installed together to comprise a larger system of modules, they produce even more direct current electrical power. They do this without making noise, emissions, or utilizing any moving gears or parts.