An underwater motor module for a water sports device is provided, which forms at least one flow channel each having at least one inlet opening and an outlet opening. The underwater motor module has a motor which is in the form of an internal rotor motor and comprises a hollow rotor, which concomitantly forms the flow channel by way of its inner side. On the outer side of the motor directed away from the flow channel is mounted outside the flow channel, and which bears blades. The motor also comprises an external stator arranged in a housing.

A power transmission coil includes a plurality of coil members each of which having a length capable of surrounding at least one power reception device located under water from all directions and that are configured to wirelessly transmit power to the power reception device. Each of the plurality of coil members includes a polygonal pipe having a polygonal shape in which a plurality of straight pipes are welded, and a conductive wire that is inserted into the polygonal pipe and is wound a plurality of times.

There are described herein methods and systems for operating an electric motor of a watercraft. In one method, the electric motor of the watercraft is controlled based on commands received from an accelerator of the watercraft, a sensor signal is received from at least one sensor of the watercraft while the electric motor is in operation, the sensor signal indicative of an undesirable condition of a water intake of the watercraft, and a change is effected to the controlling of the electric motor in response to receiving the sensor signal.

There are described herein methods and systems for operating an electric motor of a watercraft. In one method, the electric motor of the watercraft is controlled based on commands received from an accelerator of the watercraft, a sensor signal is received from at least one sensor of the watercraft while the electric motor is in operation, the sensor signal indicative of an undesirable condition of a water intake of the watercraft, and a change is effected to the controlling of the electric motor in response to receiving the sensor signal.

A Very Large Bag (VLB) suitable for containing and transporting various liquids is disclosed that includes solar arrays to generate electric power. The VLB further comprises various features useful in the transportation, navigation, and storage of liquids on very large bodies of water, such as an ocean. Such features include navigational and positioning devices, powered by solar arrays that include perovskite materials with efficiencies that exceed silicon based solar arrays. Aspects of embodiments of the present invention further include features useful for purifying or preserving the purity of the fluid being transported.

A power transmitting device transmits power to a power receiving device having a power receiving coil in water. The power transmitting device includes a power transmitting coil configured to transmit the power to the power receiving coil via a magnetic field. The power transmitting device also includes a support member that supports the power transmitting coil, and one or more spacers that hold the transmitting coil and the support member.

An underwater liquid supply unit includes a first bladder containing a first liquid, a second bladder containing a second liquid, and a third bladder containing a third liquid. The combined volume of the first liquid, second liquid, and third liquid is neutrally buoyant relative to a surrounding medium the liquid supply unit is disposed in (e.g., in seawater). As the first liquid, second liquid, and third liquid are dispensed from the bladders, the bladders may reduce in size in at least one dimension. As the liquids are dispensed, the liquids may be dispensed in a predetermined volumetric ratio based on the density of the liquids to maintain neutral buoyancy of the combined volume of liquid. The underwater liquid supply unit may also include an integrated generator such as a fuel cell, as well as a propeller.

A method for charging a battery set of an autonomous vehicle including: determining charging requirements of the battery set of the autonomous vehicle via a communication from the autonomous vehicle to a charging station, in response to the communication from the autonomous vehicle, connecting a plurality of batteries of the charging station in a first combination to match the charging requirements of the battery set of the autonomous vehicle; and charging the battery set of the autonomous vehicle using the plurality of batteries of the charging station in the first combination.

A structure equipped with a fuel cell system, wherein the structure comprises: a skirt configured to form an accumulation space between a bottom of the structure and the ground, an air supplier configured to supply off-gas, which is discharged from the fuel cell system, to at least one space selected from the group consisting of the accumulation space and an internal space of the skirt, and a pressure discharger configured to discharge pressure accumulated in the accumulation space to outside of the skirt from a lower end of the skirt, and wherein lift is imparted to the structure by supplying a predetermined amount of the off-gas from the air supplier to at least one space selected from the group consisting of the accumulation space and the internal space of the skirt.

A system includes a first charger connected to one of an aircraft, a watercraft, and a vehicle having at least one vehicle battery, a second charger connected to an on board battery pack, and at least one programmable logic controller (PLC) to: manage communication between the at least one vehicle battery and the first charger to ensure that the at least one vehicle battery reaches a preset state of charge (SOC), manage communication between the on board battery pack and the second charger to ensure that the on board battery pack reaches the preset SOC, and manage transfer of energy from the on board battery pack to the at least one vehicle battery.