How can a 12 volt battery inverter give power to a house?

An inverter converts direct current into alternating current. An inexpensive 12 volt inverter is often used to convert 12 volt direct current from a battery to 120 volt alternating current to power small household appliances during a power failure. More expensive inverter systems with large batteries are also available for use with solar panels, wind generators, or other non-commercial power sources.