Abstract: A battery cellar includes: battery groups each including a plurality of batteries; a power converter (AC/DC converter and DC/DC converter) electrically connected between the plurality of batteries and an electric power system, the power converter being capable of bidirectional power conversion; and a server that controls operation of the power converter in accordance with a DR request from the electric power system, to cause charging and discharging of a plurality of batteries. The server suppresses charging and discharging of batteries of a rank representing a smaller degree of battery degradation, relative to charging and discharging of batteries of a rank representing a greater degree of battery degradation. Proper inventory of batteries of a higher rank can thus be ensured.

Abstract: The battery cellar includes a storage cabinet that stores a plurality of batteries, a power converter (an AC/DC converter and a DC/DC converter) electrically connected between the plurality of batteries stored in the storage cabinet and a power system to perform a bidirectional power conversion operation, and a server that controls the power converter to charge or discharge the plurality of batteries in response to a DR request from the power system. The server, based on a level of demand determined in accordance with a rank related to a degradation degree of a battery, suppresses the charging/discharging of a battery with a higher demand rank among the plurality of batteries as compared with the charging/discharging of a battery with a lower demand rank among the plurality of batteries.

Abstract: The battery cellar includes a storage cabinet that stores a plurality of used batteries, a power converter (an AC/DC converter and a DC/DC converter) electrically connected between the plurality of used batteries stored in the storage cabinet and a power system, and a server that controls the power converter to charge or discharge the plurality of batteries in response to a demand response request from the power system. The server selects, from the plurality of used batteries, a first battery, the degradation degree of which has reached a reference value, and a second battery, the degradation degree of which does not reach the reference value but is predicted to reach the reference value within a predetermined period, as replacement target batteries.

Abstract: A battery cellar includes: battery groups each including a plurality of batteries; a power converter (AC/DC converter and DC/DC converter) electrically connected between the plurality of batteries and an electric power system; and a server that controls operation of the power converter in accordance with a DR request from the electric power system, to cause charging and discharging of the plurality of batteries. The battery groups include a low operating group and a high operating group that is less than or equal to the low operating group in terms of the number of types of ranks of batteries included in each battery group, where the ranks each represent a degree of battery degradation. The server suppresses charging and discharging of the plurality of batteries included in the low operating group, relative to charging and discharging of the plurality of batteries included in the high operating group.

Abstract: The battery cellar includes a storage cabinet that stores a plurality of batteries, an AC/DC converter and a DC/DC converter electrically connected between the plurality of used batteries stored in the storage cabinet and a power system, and a server that controls the AC/DC converter and the DC/DC converter. The server controls the AC/DC converter and the DC/DC converter in response to a demand response request from the power system, and evaluates a degradation degree of each of the plurality of used batteries based on a voltage and a current of each of the plurality of used batteries charged or discharged by the AC/DC converter and the DC/DC converter.

Abstract: A system for producing hydrogen gas comprises a pair of electrodes that are disposed at a predetermined water depth under water and configured to be connected to a power supply for electrolysis of water, a gas storage chamber that is disposed at the water depth, has communication holes through which surrounding water can flow in, and stores the hydrogen gas generated at a cathode of the pair of electrodes due to the electrolysis, a hydrogen recovery device disposed above the water depth, and piping configured to lead the hydrogen gas stored in the gas storage chamber to the hydrogen recovery device.

Abstract: A hydrogen gas compression system comprises a hydrogen storage chamber placed at a predetermined water depth in water to communicate with surrounding water; a hydrogen container filled with hydrogen gas by a lower pressure than a hydraulic pressure at the predetermined water depth; a transporting portion configured to guide the hydrogen container that is filled with the hydrogen gas, from above the predetermined water depth to the hydrogen storage chamber; a gas release portion configured to cause the hydrogen gas to be released from the hydrogen container transported to the hydrogen storage chamber and to be stored in the hydrogen storage chamber; a hydrogen recovery device placed above the predetermined depth; and a tube arranged to connect inside of the hydrogen storage chamber with the hydrogen recovery device.