Flywheel for energy storage, comprising a rotor, a housing enclosure, means for charging energy by transferring electric energy to stored kinetic energy in the rotating rotor and means for discharging energy by transferring stored kinetic energy in the rotating rotor to electric energy, distinctive in that the rotor is vertically oriented, the rotor has mass of over 5000 kg, the rotor comprises a central vertical shaft, a radial bearing is arranged to an upper end of the vertical shaft, an axial-radial hydraulic bearing, or separate axial and radial bearings, is arranged to a lower end of the vertical shaft.