HOUSEHOLD ELECTRICITY STORAGE SYSTEM

A residential electric power storage system includes: a lead-in wire (5); a distribution line (7); an electric power storage device (48); a voltage sensor (42) sensing a voltage of the lead-in wire (5); a current sensor (43) sensing a current charged to the electric power storage device (48) through the distribution line (7); an electric power adjustment unit (44) adjusting electric power charged to the electric power storage device (48) through the distribution line (7); and a controller (46) controlling the electric power adjustment unit (44). If the lead-in wire (5) has voltage smaller than a threshold voltage, the controller (46) controls the electric power adjustment unit (44) to match the current that is charged to the electric power storage device (48) to a command value to provide current control, whereas if the lead-in wire (5) has voltage larger than the threshold voltage, the controller (46) controls the electric power adjustment unit (44) to match the voltage of the lead-in wire (5) to a command value to provide voltage control.