A review of the research and development of dye-sensitized solar cells within the Swedish research program Angstrom Solar Center. A path towards low prodn. cost is the development of a continuous process, which allows the prodn. of solar cells in large vols. and with a high productivity. We have developed a deposition method for the prodn. of the mesoporous TiO2 electrode layer that is based on compression of a powder film at room temp. This technique allows us to use flexible substrates, a prerequisite for a continuous process. A novel interconnect technol., compatible with a continuous prodn. process, is described. Stability data of plastic dye-sensitized solar cells, exposed to indoor light for >10,000 h, demonstrates the possibility for the technol. to be explored for various types of indoor applications. Optimization of the dye-sensitized solar cells is a challenging task as it is a complex highly interacting mol. system. A system approach is proposed, where the complete dye-sensitized solar cells is investigated with a series of measurement techniques that allows the study of the internal processes under relevant conditions. Two examples of such techniques are given.