NOVELTY - A system comprises a conditioning unit; a first electroplating unit (23) to form a first layer of a precursor stack by electroplating a metal of Group IB or IIIA; a first cleaning unit (24A); a second electroplating unit (23) to form a second layer of the precursor stack by electroplating another metal of Group IB or IIIA over the first layer; a second cleaning unit (24B); and a moving assembly having a feed spool (20).    USE - For forming an absorber structure for solar cells on a front surface of a continuous flexible workpiece (claimed).    ADVANTAGE - The system provides a low-cost, high throughput two-stage process for fabrication of copper, indium, gallium, selenium type absorber layers for manufacturing of solar cells. Conditioning process results in an electroplating efficiency of more than 90% when a subsequent electroplating process is performed and the first metal layer such as a copper layer is electroplated onto the activated surface. In roll-to-roll process all depositions are done in a controlled environment (enclosure for the roll) and the time between depositions are minimized unlike a batch process that requires several loading and unloading steps to deposit a stack of materials on a base, such as copper(Cu) is plated on a section of the base, thus the surface of the plated material is fresh and active after plating and after the water rinse step, therefore, when section moves into the next plating bath, for example a gallium (Ga) or indium (In) plating bath, within a few seconds or minutes, deposition initiates on this active surface, and if the velocity of the foil base is constant, then the Ga or In plating always operates on the same Cu surface in terms of activity, thus provides highly repeatable results in terms of thickness and uniformity of the In, Ga and Cu layers.    DETAILED DESCRIPTION - A system comprises a conditioning unit to condition the front surface of continuous flexible workpiece (22) to form activated surface portions, where the activated surface portions present a consistently active surface along the continuous flexible workpiece for electroplating; a first electroplating unit (23) to form a first layer of a precursor stack by electroplating a metal of Group IB or IIIA over one of the activated surface portions of the continuous flexible workpiece as the continuous flexible workpiece is advanced through the first electroplating station; a first cleaning unit (24A) to clean the first layer deposited in the first electroplating unit; a second electroplating unit (23) to form a second layer of the precursor stack by electroplating another metal belonging to the other of the Group IB or IIIA over the first layer as the continuous flexible workpiece is advanced through the second electroplating units and while the first layer is continued to be electroplated on a following one of the activated surface portions of the surface of the continuous flexible workpiece in the first electroplating unit, where the first layer is different from the second layer; a second cleaning unit (24B) to clean the second layer deposited in the second electroplating unit; and a moving assembly to hold and linearly move the continuous flexible workpiece through the units of the system, where the moving assembly comprises a feed spool (20) to unwrap and feed unprocessed portions of the continuous flexible workpiece into the system and a take-up spool to receive processed portions and wrap them around. The system further comprises a cleaning-drying unit (25) to clean and dry the third layer and a third cleaning unit to clean the third layer deposited in the third electrodeposition unit. An INDEPENDENT CLAIM is included for forming a precursor stack on a frontside of a continuous flexible workpiece involving moving the continuous flexible workpiece into and sequentially through the conditioning unit, activated surface cleaning unit, first electroplating unit, first cleaning unit, second electroplating unit, second cleaning unit, third electroplating unit, and cleaning-drying unit by feeding the continuous flexible workpiece; conditioning the surface of the conductive layer in the conditioning unit to form an activated surface portion (where the activated surface portion presents a consistently uniform surface along an entirety of the continuous flexible workpiece for electroplating); cleaning the activated surface portion in the activated surface cleaning unit; forming a precursor stack over the activated surface portion after cleaning the activated surface portion by forming a first material layer over the activated surface portion by electrodepositing Group IB or IIIA material in the first electroplating unit; cleaning the first material layer in the first cleaning unit; forming a second material layer over the first material layer by electrodepositing Group IB or IIIA material in the second electroplating unit; cleaning the second material layer in the second cleaning unit; forming a third material layer over the second material layer by depositing another Group IB or Group IIIA material in the third electroplating unit; cleaning and drying the precursor stack in the cleaning-drying unit; and taking up and wrapping processed portion of the continuous flexible workpiece.    DESCRIPTION OF DRAWING(S) - The figure shows roll to roll electrodeposition system.    Feed spool (20)    Continuous flexible workpiece (22)    Electroplating unit (23)    First cleaning units (24A)    Second cleaning unit (24B)    Dry unit (25)    Packing sheet (26)    Packing spool. (27)