Abstract: A method for storing and releasing heat by means of a phase change material. In said method, a phase change is caused in a first heat exchanging device (4) by supplying heat during a charging process in a storage medium comprising a phase change material in order to store the heat as latent heat in the storage medium, and a phase change is caused in the storage medium while heat is dissipated during a discharging process in the first or another heat exchanging device (2).

Abstract: The invention relates to a sun protection device that has a plurality of segments that are spaced apart from one another parallel to their longitudinal direction and that are received so as to be rotatable about their longitudinal axis. The segments have respective segment top surfaces on which a plurality of optical concentrator structure elements from an at least partially transparent dielectric material, so-called CPCs (Compound Parabolic Concentrators) are provided. Said concentrators have a surface of incidence and one planar or curved receiving surface and are oriented with their receiving surface toward the segment top surface. The invention is characterized in that the segment top surface, at an angle to its longitudinal direction, is at least partially curved or edged, the segment top surface is reflecting or opaque, and the CPCs adjoin the segment top surface with their receiving surface directly or across at least one coupling layer or are spaced apart and disposed opposite the segment top surface.