Method for operating an energy installation, wherein the energy installation comprises: a wind turbine or water turbine, which is connected to a generator, a converter unit, which is connected on the generator side to the generator, and an auxiliary energy unit, which is used to provide electrical energy to cover the intrinsic energy demand of the energy installation, in which the converter unit is connected on the grid side to an electric power grid and feeds electrical energy generated by the generator into the electric power grid via the converter unit, in which the auxiliary energy unit is connected to the electric power grid for the purpose of drawing electrical energy, and in which, in the event of a separation of the converter unit and of the auxiliary energy unit from the electric power grid, the auxiliary energy unit draws electrical energy from an energy storage unit, and in which, in the event of the separation of the converter unit and of the auxiliary energy unit from the electric power grid, the auxiliary energy unit draws electrical energy from the energy storage unit for an adjustable period of time, and the auxiliary energy unit then draws electrical energy generated by the generator via the converter unit, characterized in that the energy storage unit is formed as a capacitive energy store or as a battery and the capacitive energy store or the battery is electrically charged by a charging unit, and in the event of the separation of the converter unit and of the auxiliary energy unit from the electric power grid, the charging unit draws electrical energy generated by the generator via the converter unit and/or draws from a photovoltaic unit and/or from a wind energy unit. a wind turbine or water turbine, which is connected to a generator, a converter unit, which is connected on the generator side to the generator, and an auxiliary energy unit, which is used to provide electrical energy to cover the intrinsic energy demand of the energy installation, in which the converter unit is connected on the grid side to an electric power grid and feeds electrical energy generated by the generator into the electric power grid via the converter unit, in which the auxiliary energy unit is connected to the electric power grid for the purpose of drawing electrical energy, and in which, in the event of a separation of the converter unit and of the auxiliary energy unit from the electric power grid, the auxiliary energy unit draws electrical energy from an energy storage unit, and in which, in the event of the separation of the converter unit and of the auxiliary energy unit from the electric power grid, the auxiliary energy unit draws electrical energy from the energy storage unit for an adjustable period of time, and the auxiliary energy unit then draws electrical energy generated by the generator via the converter unit, characterized in that the energy storage unit is formed as a capacitive energy store or as a battery and the capacitive energy store or the battery is electrically charged by a charging unit, and in the event of the separation of the converter unit and of the auxiliary energy unit from the electric power grid, the charging unit draws electrical energy generated by the generator via the converter unit and/or draws from a photovoltaic unit and/or from a wind energy unit.