An installation for storing thermal energy which can be obtained, for example, at times of overcapacities, from regenerative energy and then be stored is provided. The energy stored in a heat accumulator, a cold accumulator and in an additional heat accumulator can be, when needed, reconverted into electrical energy by circuits via a generator (G) while using a compressor and a turbine. The working gas is humidified by a humidification column, ideally until saturation, whereby, advantageously, a greater mass flow can be obtained at a lower volume flow. For this reason, more economical components can be used while simultaneously a high yield of the installation is achieved.