NOVELTY - The method comprises feeding (302) a continuous web of the photovoltaic cell metallic substrate towards a first fixed-abrasive filament roller brush that comprises filaments containing first fixed abrasive particles having an average size of 5-20 micrometers, contacting (306) the substrate surface with the first brush while rotating the first brush such that some defects are removed from the substrate surface by the first brush to form a polished substrate surface, and delivering (304) cooling liquid into a pinch area between the first brush and the web.    USE - The method is useful for processing a photovoltaic cell metallic substrate to remove surface defects such as pits, bump, protrusions, inclusions, rolling grooves and residues from a substrate surface.    ADVANTAGE - The method is capable of efficiently and economically processing the photovoltaic cell metallic substrate without any surface defects thus increasing the efficiency and performance of the photovoltaic cell.    DETAILED DESCRIPTION - The method comprises feeding (302) a continuous web of the photovoltaic cell metallic substrate towards a first fixed-abrasive filament roller brush that comprises filaments containing first fixed abrasive particles having an average size of 5-20 micrometers, contacting (306) the substrate surface with the first brush while rotating the first brush such that some defects are removed from the substrate surface by the first brush to form a polished substrate surface, delivering (304) cooling liquid into a pinch area between the first brush and the web, contacting the substrate surface with a second fixed-abrasive filament roller brush while rotating the second brush such that additional surface defects are removed from the polished substrate surface by the second brush, cleaning the web by passing the web through cleaning stations consisting of a high pressure water jet, a drying air knife, a rinsing jet, a rotating non-abrasive cleaning brush and a set of two roller brushes to clean both sides of the substrate with a surfactant containing water solution, and depositing a photovoltaic absorber layer on the polished substrate surface. The continuous web is fed at between 1 foot per minute and 20 feet per minute, is partially supported in an area of contacting with the first brush, and is supported by a stainless steel support roller. The first brush rotates at 700-1400 RPM and in a direction counter to the feeding direction of the substrate, and has a diameter of 10 inches, is a close-wound coil type brush. An average length of the filaments is larger than a gap between a brush core of the first brush and the substrate surface by 0.1-0.5 inches, and a diameter of filaments is 0.005-0.030 inches. A loading of the first fixed abrasive particles in the filaments is 20-35%. During the contacting operation, an average temperature of the cooling liquid stays under a temperature limit (50 degrees C) set to prevent substantial separation of the first fixed abrasive particles from the filaments. A gloss of the substrate surface measured at 20 degrees is doubled during the contacting operation. The metallic substrate has a thickness of 0.5-15 mils, and a width of 0.3-3 meters. A rotational axis of the first brush is parallel to the substrate surface. The second brush rotates in an opposite direction relative to the first brush with reference to the substrate surface. The rotational axes of the first brush and the second brush are substantially parallel to the substrate surface. The second brush rotates in the same direction as the feeding direction of the substrate. The second brush comprises second fixed abrasive particles that are smaller on average than the first fixed abrasive particles. An INDEPENDENT CLAIM is included for an apparatus for processing a photovoltaic cell metallic substrate to remove surface defects from a substrate surface.    DESCRIPTION OF DRAWING(S) - The diagram shows a flowchart for processing a photovoltaic cell metallic substrate to remove surface defects from the substrate surface.    Feed substrate (302)    Deliver cooling liquid (304)    Contact substrate with roller brush (306)    Additional polishing (308)    Clean substrate. (310)