Electric power supply system

An electric power supply system comprising:

• a hydrogen generation unit;
• a hydrogen storage unit including a first hydrogen tank, a second hydrogen tank, and a third hydrogen tank that store hydrogen obtained by the hydrogen generation unit;
• a holding unit including a first holding device that holds the first hydrogen tank, a second holding device that holds the second hydrogen tank, and a third holding device that holds the third hydrogen tank;
• and
• a fuel cell configured to generate electric power based on hydrogen supplied from the hydrogen storage unit, wherein
• each of the first hydrogen tank, the second hydrogen tank, and the third hydrogen tank holds a hydrogen storage alloy therein and stores hydrogen by absorption,
• for a hydrogen tank that receives hydrogen supplied from the hydrogen generation unit among the first hydrogen tank, the second hydrogen tank, and the third hydrogen tank, a valve between the hydrogen tank and the hydrogen generation unit is opened, and a valve between the hydrogen tank and the fuel cell is closed during the reception of supplied hydrogen,
• for a hydrogen tank that supplies hydrogen to the fuel cell among the first hydrogen tank, the second hydrogen tank, and the third hydrogen tank, a valve between the hydrogen tank and the hydrogen generation unit is closed, and a valve between the hydrogen tank and the fuel cell is opened during the hydrogen supply, and
• for a hydrogen tank that does not receive hydrogen supplied from the hydrogen generation unit and does not supply hydrogen to the fuel cell among the first hydrogen tank, the second hydrogen tank, and the third hydrogen tank, a valve between the hydrogen tank and the hydrogen generation unit is closed, a valve between the hydrogen tank and the fuel cell is closed, and the hydrogen tank is removably held by the holding unit.