The Cu(In,Ga)Se2 (CIGS) on glass technology is already heading towards industrial maturity, but to meet the production cost target of below 0.6 €/Wp in mid-term and below 0.4 €/Wp in long-term, development of highly efficient flexible modules is an attractive option. The ultimate advantage of thin-film technology is the possibility of monolithically connected flexible modules produced with high speed roll-to-roll manufacturing systems. Partners of this proposal have already demonstrated a record efficiency of 14.1% for cells on polyimide and >15% efficiency cells on metal foil using “static deposition” processes. However, transfer of “static deposition” process to “in-line deposition” on moving substrates brings additional challenges for control of layer composition and interfaces. Choice of appropriate substrate and deposition processes to overcome problems of thermal mismatch-related stress are important for high performance and monolithic cell interconnection. The main goal of the project is to develop innovative flexible substrates and deposition processes suitable for the in-line and/or roll-to-roll production of highly efficient solar modules using thinner (< 1 micron) CIGS absorbers and with potential for production costs below 0.6 €/Wp in future. The objective will be achived by developing novel concepts in growth of “high quality” layers and interfaces for efficiency improvement, aiming a new world record efficiency of 16% on polyimide and low-cost metal (mild steel and Al-based) foils. Also, the implementation of in-line compatible buffer, improvements in interconnect technologies and application of multifunctional top layer will lead to an advancement towards roll-to-roll manufacturability of integrated solar modules. This project will help research institutions to maintain a Global lead in CIGS field and will enable the European industries to implement the research excellence in industrial production of low cost flexible CIGS solar modules in future.