Abstract: The invention relates to a thermal storage system for storing thermal energy, comprising a solid storage which comprises a plurality of storage blocks with their outer sides arranged relative to one another, wherein the storage blocks comprise at least one continuous opening arranged in the longitudinal direction and/or at least one recess formed in the longitudinal direction at their outer side, and are arranged relative to one another such that at least one channel comprising an inlet opening and an outlet opening spaced apart from the inlet opening is formed by the recess and/or the continuous opening, a heat-carrying medium which is at least in portions in direct contact with the channel, a charging circuit comprising a first supply means connected to the inlet opening of the channel for supplying thermally charged heat-carrying medium and a first draining means connected to the outlet opening and/or a discharge circuit comprising a second draining means connected to the inlet opening of the channel for d