Method and device for generating electrical energy

An apparatus for generating electrical energy comprising a system comprising a power plant and an air treatment plant, wherein the power plant has a gas expansion unit, which is connected to a generator for generating the electrical energy, and

• wherein the air treatment plant has
• an air compression unit for compressing a feed air to form a compressed feed air,
• a heat exchanger system for cooling the compressed feed air to form a cooled and compressed feed air,
• means for introducing the compressed feed air into the heat exchanger system,
• means for producing a storage fluid from the cooled and compressed feed air from the heat exchanger system,
• a liquid tank for storing the storage fluid as a cryogenic liquid,
• means for removing said cryogenic liquid from the liquid tank,
• means for increasing the pressure of the cryogenic liquid removed from the liquid tank to form a cryogenic liquid at an elevated pressure, and
• means for generating a gaseous high-pressure storage fluid by vaporizing or pseudo-vaporizing the cryogenic liquid at an elevated pressure,
• said apparatus further comprising:
• means for introducing the gaseous high-pressure storage fluid into the gas expansion unit, and
• a control device and control elements for operating the system in a first and in a second operating mode, wherein
• in the first operating mode
• in the air treatment plant
• the feed air is compressed in the air compression unit and cooled in the heat exchanger system,
• the storage fluid produced from the cooled and compressed feed air contains less than 40 mol % of oxygen, and
• the storage fluid produced from the cooled and compressed feed air is stored as the cryogenic liquid in the liquid tank,
• and in the second operating mode
• the cryogenic liquid is removed from the liquid tank and the removed cryogenic liquid is vaporized or pseudo-vaporized at superatmospheric pressure to generate the gaseous high-pressure storage fluid, and the gaseous high-pressure storage fluid is expanded in the gas expansion unit,
• said apparatus further comprising:
• means for introducing gaseous natural gas into the heat exchanger system, and
• wherein in the second operating mode, the control device and the control elements operate to
• introduce the gaseous natural gas into the heat exchanger system, where the gaseous natural gas is liquefied or pseudo-liquefied, and
• the vaporizing or pseudo-vaporizing of the cryogenic liquid is carried out in the heat exchanger system.