In hydrogenated amorphous silicon solar cells of 100 cm2, the conversion efficiency of more than 6% has been obtained for the cells with metal/n‐i‐p/ITO/glass and ITO/n‐i‐p/SS structures under AM1 (100 mW/cm2) illumination. The module structure and encapsulating materials suitable for a‐Si solar cell were investigated to make a low cost module. Typical output power under AM1 illumination is 16W for the module composed of 40 sheets of ITO/n‐i‐p/SS cells with area. The a‐Si modules have been tested in various environments. The results show that the a‐Si solar cells are highly resistive to high and low temperature, high humidity environments, and thermomechanical stress.