Server device

A server device comprising:

• a communication unit;
• and
• a control unit that performs communication using the communication unit, wherein:
• the control unit sends a movement instruction to a first power supply vehicle to move to a position of a power supply subject vehicle that requires power supply when a traffic situation around the power supply subject vehicle is a first situation;
• and
• the control unit sends a movement instruction to a second power supply vehicle to move to the position of the power supply subject vehicle when the traffic situation is a second situation in which a degree of congestion is higher than the first situation, the second power supply vehicle having a higher power generation capacity than the first power supply vehicle, wherein
• the first power supply vehicle is equipped with only a battery,
• the second power supply vehicle is equipped with a battery and a power generation device, and
• the second power supply vehicle uses fuel to generate electricity with the power generation device.