NOVELTY - An optically transparent element comprises an optically transparent substrate and an anti-reflective coating (c1) disposed on surface of the substrate, the anti-reflective coating comprises polymer (p1) comprising tetraalkoxy silane residue and second alkoxy silane residue selected from trialkoxy silanes, dialkoxy silanes and/or monoalkoxy silanes where the polymer comprises at least 50 mole.% of the tetraalkoxy silane residue based on the total moles of polymer and the coating comprises polymer particles having an average size of not greater than 100 nm.    USE - For producing anti-reflective coating (claimed) used in the manufacture of photovoltaic (PV) modules (claimed); for glass covers used in photovoltaic cell applications.    ADVANTAGE - The anti-reflective (AR) coating reduces reflections of the incident light and permits more light to reach the thin film semiconductor film of the photovoltaic module thus permitting the device to act more efficiently.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) photovoltaic module comprising at least one semiconductor layer; an optically transparent layer disposed over the semiconductor layer; and the anti-reflective coating (c1) disposed on at least one surface of the optically transparent substrate;    (2) method of producing a coating solution involving combining first tetraalkoxy silane material, second alkoxy silane material, base catalyst and solvent to form a coating, maintaining the pH of the coating solution for a sufficient period of time at a sufficient temperature to form polymer particles having an average particle size of 15-100 nm; and reducing the pH of the coating solution to less than 5;    (3) method of forming an optically transparent element involving dispensing the coating solution an optically transparent substrate; and curing the coating solution to form an anti-reflective coating on the optically transparent substrate;    (4) anti-reflective coating solution comprising the polymer (p1); a solvent, where the coating solution has a polymer particle concentration of up to 25 wt.% and a viscosity of not greater than 2 cP, and where the coating solution has a viscosity of not greater than 2 cP and a pH of not greater than 5 for at least 24 hours at 25 degrees C.