With millions of square meters of available flat roof surfaces with PV conversion potential, PV roofing membranes have a huge potential for mass deployment. However, currently, major issues still hinder this deployment: adhesives or barrier encapsulants of the existing flexible PV roofs don’t meet yet the same reliability as standard construction materials and BIPV is still expensive. The PV-GUM project aims at developing new manufacturing technologies and equipments which will produce a low cost highly efficient flexibly BIPV solar cell on a bituminous roofing membrane (thanks to their proven sustainability, bituminous membranes remain predominantly used for waterproofing flat roofs). The PV-GUM membrane should be very close to the usual bituminous roofing membrane in terms of size, installation process and quality to highly increase the penetration power of PV-GUM in the building market. The PV-GUM membrane will be based on the “Derbibrite” white-coated bituminous membrane technology of Imperbel, PV-GUM coordinator, and the Flexcell flexible PV modules technology. The full integration of the flexible PV modules in the membrane will be performed at the manufacturing stage by a new standardized roll-to-roll encapsulation process to produce PV-laminates followed by a roll-to-roll bitumen impregnation of the PV-laminates. In parallel, a new standardized PECVD reactor and process will be implemented to increase the Flexcell PV cells efficiency to 8% at least and achieve technology superiority over Unisolar remaining the main supplier for this market. The PV-GUM project targets a PV-laminates production capacity of 20 MW. The high degree of integration of the PV modules and the roll-to-roll lamination allowing process automation will highly decrease the costs /Wp. Furthermore, sustainability, quality procedures and monitoring in line, compliance to BIPV standards, as well as fully recyclability of the whole product are associated priorities of PV-GUM.