A method for storing energy by converting into thermal energy and subsequently producing electricity by means of - a gas turbine set having a compressor, expander, and electrical generator, by means of at least one first and one second low-temperature store, - and a high-temperature store having a bulk material as a thermal reservoir, the electrical energy being stored in a high-temperature store in the form of high-temperature heat above the turbine outlet temperature TOT, and during the electricity generation phase, a compressed gas from the compressor being heated to a temperature near the turbine outlet temperature TOT in a low-temperature store (3, 4), and being subsequently heated to a temperature level of at least the turbine inlet temperature TIT by means of heat stored from electricity in a high-temperature store, characterized in that the ratio between the packing height in the flow direction and the average particle diameter of the bulk material in the high-temperature store is at least 10, preferably at least 100, more preferably at least 250, even more preferably at least 500, and particularly preferably at least 1000, and that at the end of a discharge phase, before the gas turbine comes to a stop, valves and, or valves and, are closed in such a manner that the high-temperature store, low-temperature store or low-temperature store, and the turbine remain nearly under operating pressure. - a gas turbine set having a compressor, expander, and electrical generator, by means of at least one first and one second low-temperature store, - and a high-temperature store having a bulk material as a thermal reservoir, the electrical energy being stored in a high-temperature store in the form of high-temperature heat above the turbine outlet temperature TOT, and during the electricity generation phase, a compressed gas from the compressor being heated to a temperature near the turbine outlet temperature TOT in a low-temperature store (3, 4), and being subsequently heated to a temperature level of at least the turbine inlet temperature TIT by means of heat stored from electricity in a high-temperature store, characterized in that the ratio between the packing height in the flow direction and the average particle diameter of the bulk material in the high-temperature store is at least 10, preferably at least 100, more preferably at least 250, even more preferably at least 500, and particularly preferably at least 1000, and that at the end of a discharge phase, before the gas turbine comes to a stop, valves and, or valves and, are closed in such a manner that the high-temperature store, low-temperature store or low-temperature store, and the turbine remain nearly under operating pressure. the electrical energy being stored in a high-temperature store in the form of high-temperature heat above the turbine outlet temperature TOT, and during the electricity generation phase, a compressed gas from the compressor being heated to a temperature near the turbine outlet temperature TOT in a low-temperature store (3, 4), and being subsequently heated to a temperature level of at least the turbine inlet temperature TIT by means of heat stored from electricity in a high-temperature store, characterized in that the ratio between the packing height in the flow direction and the average particle diameter of the bulk material in the high-temperature store is at least 10, preferably at least 100, more preferably at least 250, even more preferably at least 500, and particularly preferably at least 1000, and that at the end of a discharge phase, before the gas turbine comes to a stop, valves and, or valves and, are closed in such a manner that the high-temperature store, low-temperature store or low-temperature store, and the turbine remain nearly under operating pressure.