There are many components that make up a complete solar system, but the 4 main items are: solar modules, charge controller(s), batteries and inverter(s). The solar modules are physically mounted on a mount structure ( and the DC power they produce is wired through a charge controller before it goes on to the battery bank where it is stored. The two main functions of a charge controller are to prevent the battery from being overcharged and eliminate any reverse current flow from the batteries back to the solar modules at night. The battery bank stores the energy produced by the solar array during the day for use at anytime of day or night. Batteries come in many sizes and grades. The inverter takes the DC energy stored in the battery bank and converts it to 230 VAC to run your AC appliances.