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AssigneeEcole Polytechnique Federale de Lausanna (EPFL)
InventorsAlfred Rufer, Daniel Favrat, Philippe Barrade, Sylvain Lemofouet
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Different types of energy storage systems are described, in particular hydro-pneumatic storage systems. In one, energy is stored by compressing gas in a chamber (44,45,54,55) with a liquid piston and released by gas expansion. A spray head or grid at the top of the chamber (44,45,54,55) supplies liquid as a shower through the gas being compressed or expanding in the cylinder (11,12) to maintain an isothermal condition. In another, energy is stored from an array of solar cells connected to an array of supercapacitors forming an auxiliary storage, and a main energy storage device such as a hydro-pneumatic storage system, for supply to an AC or DC network. The efficiency is improved by connecting the solar cells via the array of supercapacitors to the AC or DC network. An immersed hydro-pneumatic storage device for off-shore/on-shore power generation systems comprises a cylinder that is immersed in a liquid mass, wherein energy is stored by compressing gas with a liquid piston and energy is released by gas expansion. The mass of liquid maintains an isothermal condition in the cylinder during compression and expansion.
1-8. (canceled)
An energy storage device wherein energy from an array of solar cells is storable in a main storage, in particular a hydro-pneumatic storage or any other main energy storage means such as a battery or a flywheel, and in an auxiliary storage comprising an array of supercapacitors, wherein the main and auxiliary storages are alternately operable in first and second charging sequences, wherein in the first charging sequence the main storage is disconnected from the solar cells and the array of supercapacitors is charged from the array of solar cells, and in the second charging sequence the main storage is connected to be charged by the array of solar cells while the array of supercapacitors discharges, the main storage and auxiliary storages being connectable to an AC or DC network,
An immersed hydro-pneumatic energy storage device, comprising a cylinder (5a,b,c) that is immersed in a liquid mass, wherein energy is stored by compressing gas (6a,b,c) in the cylinder with a liquid piston (7a,b,c) and energy is released by gas expansion acting on the liquid piston, and wherein the mass of liquid (8) in which the cylinder is immersed maintains an essentially isothermal condition in the cylinder during compression and expansion of the gas.
Dependencies are inferred from the claim text.