NOVELTY - The plant (10) comprises a system (12) for electrothermal production of prussic acid. The system is connected to a system (14) for generating electricity by lines (26, 28), where the lines supply the product gas of the electrothermal production system to the electricity generation system. The electricity generation system includes a fuel cell to generate electricity, and a power plant with a gas turbine, which is operated with hydrogen and/or hydrocarbon-containing gases. The power plant is gas or steam turbine power plant.    USE - The integrated plant is useful in gas, coal and nuclear power stations.    ADVANTAGE - The plant ensures flexible storage and use of electrical energy.    DETAILED DESCRIPTION - The plant (10) comprises a system (12) for electrothermal production of prussic acid. The system is connected to a system (14) for generating electricity by lines (26, 28), where the line supplies the product gas of the electrothermal production system to the electricity generation system. The electricity generation system includes a fuel cell to generate electricity, and a power plant with a gas turbine, which is operated with hydrogen and/or hydrocarbon-containing gases. The power plant is gas or steam turbine power plant. The electrothermal production system comprises an arc reactor, a reactor with electrical coke fluidized bed, an electrically heated reactor with a platinum-based catalyst, and a device for separating the gaseous mixture obtained from the electrothermal production of the prussic acid. The plant further comprises a storage unit (24) for hydrogen and/or hydrocarbon-containing gases. The storage unit is connected with the electrothermal production system and the electricity generation system via the lines. The electrothermal production system further comprises a steam generator to generate steam from the waste heat of the electro-thermal process. The plant is connected to a weather forecast unit. An INDEPENDENT CLAIM is included for a method for flexible use of electricity.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of an integrated plant.    Integrated plant (10)    Electrothermal production system (12)    Electricity generation system (14)    Storage (24)    Lines. (26, 28)