Inverters
Inverters are used to convert the low voltage direct current that is stored in the battery bank, into high voltage alternating current that is used in household wiring systems. The type of electricity that inverters produce is similar to "mains" or "grid" electricity and can actually be of a better quality. The voltage and frequency of the inverters is usually governed by local standards which dictate the kind of electrical equipment available.
In grid connected systems, the inverter harvests the energy produced by the solar panels directly and either feeds this into the house or the grid, depending on the energy demand from the house.