Power supply system and method of controlling the same
A power supply system includes: a hydrogen generation device that uses electric power to generate hydrogen; a hydrogen storage device that stores hydrogen generated by the hydrogen generation device; a fuel cell system that uses hydrogen stored in the hydrogen storage device to generate electric power; a power storage device; and a control device executing at least one of first control and second control based on an electricity expense, the first control controlling a first ratio between electric power to be supplied from a natural energy power generation device to the hydrogen generation device and electric power to be supplied from the natural energy power generation device to the power storage device, the second control controlling a second ratio between electric power to be supplied from the power storage device to a load and electric power to be supplied from the fuel cell system to the load.
1. A power supply system connected to an electric power system, a natural energy power generation device, and a load, the system comprising:
a hydrogen generation device that uses electric power to generate hydrogen;
a hydrogen storage device that stores hydrogen generated by the hydrogen generation device;
a fuel cell system that uses hydrogen stored in the hydrogen storage device to generate electric power;
a power storage device; and
a control device executing at least one of first control and second control based on an electricity expense, the first control controlling a first ratio between electric power to be supplied from the natural energy power generation device to the hydrogen generation device and electric power to be supplied from the natural energy power generation device to the power storage device, the second control controlling a second ratio between electric power to be supplied from the power storage device to the load and electric power to be supplied from the fuel cell system to the load.
2. The power supply system according to claim 1 , wherein in the first control, the control device controls the first ratio so that the electricity expense is reduced.
3. The power supply system according to claim 1 , wherein in the second control, the control device controls the second ratio so that the electricity expense is reduced.
4. The power supply system according to claim 1 , wherein the control device executes the first control in a time period during which surplus electric power in the natural energy power generation device is less than a total of electric power that is capable of being stored in the power storage device and electric power that is capable of being received by the hydrogen generation device.
5. The power supply system according to claim 1 , wherein the control device executes the first control before a time period during which surplus electric power in the natural energy power generation device peaks to control the first ratio so that free capacity by which the power storage device is capable of being charged remains after the time period during which surplus electric power peaks.
6. The power supply system according to claim 1 , wherein the control device executes the second control in a time period during which electric power demanded by the load is less than a total of electric power that is capable of being released from the power storage device and electric power that is capable of being generated by the fuel cell system.
7. The power supply system according to claim 1 , wherein the control device executes the second control before a time period during which surplus electric power in the natural energy power generation device peaks on a negative side to control the second ratio so that capacity by which the power storage device is capable of being discharged remains after a time period during which electric power demanded by the load peaks.
8. A method of controlling a power supply system connected to an electric power system, a natural energy power generation device, and a load, the method comprising:
generating hydrogen in a hydrogen generation device by using surplus electric power in the natural energy power generation device;
storing generated hydrogen in a hydrogen storage device;
generating electric power in a fuel cell system by using hydrogen stored in the hydrogen storage device;
charging a power storage device by using surplus electric power in the natural energy power generation device;
discharging the power storage device; and
executing at least one of first control and second control based on an electricity expense, the first control controlling a first ratio between electric power to be supplied from the natural energy power generation device to the hydrogen generation device and electric power to be supplied from the natural energy power generation device to the power storage device, the second control controlling a second ratio between electric power to be supplied from the power storage device to the load and electric power to be supplied from the fuel cell system to the load.