Abstract: An arrangement for the storage of energy in power plants in which an excess of water during low-load operation is heated in feed water preheaters, and is stored as hot water in a hot storage vessel. During peak-load operation, the hot water from the storage vessel is fed into a feed water line, bypassing the feed water preheaters. Alternately with the hot water, colder water is taken from or stored in the lower portion of the hot storage tank. Before being fed into the hot storage tank, the colder water is thermally degassed with bleeder steam at a pressure slightly above atmospheric pressure, preferably between 1.01 and 1.5 atmospheres (abs). The feed water tank connected to the degasser is used for volume compensation while storing the hot water in the hot water storage tank. The storage tank may be in the form of three units of substantially identical volume. The hot storage tank and the feed water tank used as warm-water storage, are alternately filled and emptied.