POWER SUPPLY SYSTEM

A power conditioner, converting DC power supplied by a solar cell into AC power and outputting the power, includes a grid-connected output part and a grid independent outlet. During a normal state in which a commercial power supply supplies AC power, grid-connected output part supplies AC power to a main electric line and branch electric lines to which commercial power supply is connected. During a power failure state in which supply of AC power by commercial power supply is stopped, grid independent outlet supplies AC power to a charge-discharge unit. Power conditioner performs grid-connected operation during the normal state, and performs grid independent operation during the power failure state. The charge-discharge unit, during the power failure state, charges a storage cell unit with AC power supplied through grid independent outlet or supplies, to appliances, AC power supplied through grid independent outlet.