There is provided a fuel cell system which can be started quickly, the configuration of which can be simplified and which enables cost reduction. The fuel cell system is a fuel cell system including a first power supply organizer, the first power supply organizer including a plurality of fuel cell stacks, an oxidant gas channel distributing and supplying oxidant gas to each of the fuel cell stacks, and an air supplier provided for each of the fuel cell stacks, wherein a battery is electrically connected to at least the air supplier of a fuel cell stack connected to the oxidant gas channel on a most upstream side among the plurality of fuel cell stacks.

Provided is a reducing gas detection sensor which has sensitivity improved as compared to that of the related art, and in which power consumption is decreased. The reducing gas detection sensor includes: a reducing gas detection material including a palladium compound and a carbon compound, and having reactivity with a reducing gas; and a unit configured to measure a conductivity of the reducing gas detection material.

Devices and methods for managing the state of health of an electrolyte in redox flow batteries (RFB) efficiently are described. A diffusion cell is added to the RFB which controls one or more properties of the electrolytes using the diffusion of protons through a proton exchange membrane. The diffusion cell can resemble an electrochemical cell in that there are two fluid chambers divided by a proton conducting membrane. Anolyte flows through one side of the device where it contacts the proton conducting membrane, and catholyte flows through the second side of the device where it contacts the other face of the proton conducting membrane. The concentration gradient of protons from high concentration in the catholyte to low concentration in the anolyte is the driving force for proton diffusion, rather than electromotive force, which greatly simplifies the design and operation.

Devices and methods for managing the state of health of an electrolyte in redox flow batteries (RFB) efficiently are described. A diffusion cell is added to the RFB which controls one or more properties of the electrolytes using the diffusion of protons through a proton exchange membrane. The diffusion cell can resemble an electrochemical cell in that there are two fluid chambers divided by a proton conducting membrane. Anolyte flows through one side of the device where it contacts the proton conducting membrane, and catholyte flows through the second side of the device where it contacts the other face of the proton conducting membrane. The concentration gradient of protons from high concentration in the catholyte to low concentration in the anolyte is the driving force for proton diffusion, rather than electromotive force, which greatly simplifies the design and operation.

A fuel cell system that can offer fuel efficiency and water drainage performance which are compatible with each other, the fuel cell system including a fuel cell stack; a fuel gas supply device; a gas-liquid separator; a pressure measuring device; and a controlling unit, wherein the controlling unit controls pulsed operation of the fuel gas supply device in such a way that a measured pressure is within the range of a preset upper limit pressure and lower limit pressure, and the controlling unit uses a flow rate increasing control at least once when the pressure rises in the pulsed operation before the pressure reaches the upper limit pressure, as long as the pressure does not exceed the upper limit pressure, the flow rate increasing control being to increase the supply of the fuel gas supplied by means of the fuel gas supply device.

A power controlling apparatus includes a secondary battery (2) connected to an electrical device (4), and a fuel cell (3) connected to the electrical device (4) and the secondary battery (2). The fuel cell (3) has two non-generating modes including an idling mode and a halt mode, the fuel cell (3) suspending generation of power while being supplied with fuel in the idling mode, the fuel cell (3) stopping generation of power without fuel supply in the halt mode. The power controlling apparatus further includes a remainder estimator (11) to calculate the remaining number of starts representing the remaining number of available starts of the fuel cell (3), and a controller (16) to control the fuel cell (3) to be one of the two non-generating modes during a non-charging mode of the secondary battery (2), based on the remaining number of starts calculated by the remainder estimator (11).

A power controlling apparatus includes a secondary battery (2) connected to an electrical device (4), and a fuel cell (3) connected to the electrical device (4) and the secondary battery (2). The fuel cell (3) has two non-generating modes including an idling mode and a halt mode, the fuel cell (3) suspending generation of power while being supplied with fuel in the idling mode, the fuel cell (3) stopping generation of power without fuel supply in the halt mode. The power controlling apparatus further includes a remainder estimator (11) to calculate the remaining number of starts representing the remaining number of available starts of the fuel cell (3), and a controller (16) to control the fuel cell (3) to be one of the two non-generating modes during a non-charging mode of the secondary battery (2), based on the remaining number of starts calculated by the remainder estimator (11).

Provided are a marine testbed and a marine test method for providing marine verification and securing a track record of an eco-friendly propulsion system for a ship, wherein the marine testbed and the marine test method test and evaluate applicability of a hybrid propulsion system to the ship and facilitate securing of a track record, the hybrid propulsion system utilizing a battery, a fuel cell, a zero-carbon fuel engine, a zero-carbon fuel mixed-combustion engine, and a heterogeneous eco-friendly alternative fuel for the ship which are essential for developing an eco-friendly ship.

Provided are a marine testbed and a marine test method for providing marine verification and securing a track record of an eco-friendly propulsion system for a ship, wherein the marine testbed and the marine test method test and evaluate applicability of a hybrid propulsion system to the ship and facilitate securing of a track record, the hybrid propulsion system utilizing a battery, a fuel cell, a zero-carbon fuel engine, a zero-carbon fuel mixed-combustion engine, and a heterogeneous eco-friendly alternative fuel for the ship which are essential for developing an eco-friendly ship.

A fuel cell system is equipped with a fuel cell and a secondary battery. This fuel cell system is equipped with a recordation unit that records a charge-discharge history of the secondary battery, a prediction unit that predicts restriction on an output of the secondary battery based on the charge-discharge history recorded by the recordation unit, and an output control unit that starts power generation by the fuel cell prior to a timing of restriction on the output of the secondary battery, when the prediction unit predicts restriction on the output of the secondary battery and the fuel cell is in an intermittent operation state.