Similar to the classical solution of hydraulic pump-turbine plant, new means for accumulation of eletrical energy are given for lower but respectable quantities by the so called BESS (Battery Energy Storage System) and SMES (Super conducting Magnet Energy Storage). Another energy accumulator is given by using mecanichal kinetic energy of fly-wheel. Each system has advantages and disadvantage from the point of wiew of the quantity of stored energy and magnitude of the instantaneous usable power. A realistic application of energy storage, using the advantages of their complementarity. The modern energy conversion techniques allow fast, and flexible power control, and also reactive power compensation.