An energy accumulation, a distribution system and an energy accumulator that accumulates waste energy. A first energy interface is adapted for receiving first waste energy to be accumulated from a braking power reserve. A second energy interface is adapted for receiving second waste energy to be accumulated from a power generation reserve. An energy store is adapted for accumulating said received first and second waste energy. A third energy interface is adapted for providing the accumulated waste energy to at least one of an auxiliary energy exchanger and a main steam line so as to distribute the accumulated energy. A corresponding method, computer program, and computer program product and are also provided.