In this paper the work and current findings about thin film solar cell technology––CISCuT (CuInS2 on Cu-tape) is reviewed. Taking current market requirements into account it is shown that CISCuT based solar cells and modules could satisfy the demands of the market. The results of this study show that especially flexible and lightweight cells and modules should be made available on the basis of CISCuT. The innovative reel-to-reel technology to make quasi-endless tapes of solar cells and the inseparable connected unique absorber growth is explained in more detail. It is shown that the growth process can be monitored and even be controlled by means of an on-line measurement of electrical properties, which are strongly correlated to the properties of the final solar cell. Investigations and modelling of cell physics result in a p-i-n like cell structure of the CISCuT solar cells. The efficiency potential is explained for this device connected with an outlook for further improvement of the cell performance. The current batch of cells with an efficiency of about 9% is demonstrated connected with an appropriate stability of cells. The efficiency losses during the module assembling process are discussed. Efficiencies of test modules up to 7% are reported.