A method for processing a thin film photovoltaic module. The method includes providing a plurality of substrates, each of the substrates having a first electrode layer and an overlying absorber layer composed of copper indium gallium selenide (CIGS) or copper indium selenide (CIS) material. The absorber material comprises a plurality of sodium bearing species. The method maintains the plurality of substrates in a controlled environment after formation of at least the absorber layer through one or more processes up to a lamination process. The controlled environment has a relative humidity of less than 10% and a temperature ranging from about 10 Degrees Celsius to about 40 Degrees Celsius. The method subjects the plurality of substrates to a liquid comprising water at a temperature from about 10 Degrees Celsius to about 80 Degrees Celsius to process the plurality of substrates after formation of the absorber layer. The plurality of substrates having the absorber layer is subjected to an environment having a relative humidity of greater than about 10% to a time period of less then four hours.