NOVELTY - A substrate (615) has an array of solar cells (610) that are encapsulated by a cover (605). A layer of polymeric material is provided between the cover and the substrate. An optical filter affixed to the cover, is positioned on the solar cells, to preferentially transmit desired range of wavelengths of light.    USE - Reference module device for testing crystalline silicon solar cell e.g. microcrystalline silicon film, amorphous silicon film solar cell, polycrystalline silicon film solar cell such as copper indium diselenide (CIS), cadmium telluride (CdTe), copper indium gallium selenium (CIGS) type solar cells, single-crystalline type solar cell, single-crystalline thin film type solar cell such as gallium arsenide (GaAs), and multicrystalline type solar cell. Can also be used in testing III-V type solar cell, thin film chalcogenide solar cell, amorphous or nanocrystalline silicon solar cell, photochemical type solar cell, and organic type solar cell.    ADVANTAGE - Provides long lasting reference module that matches current output of solar cells being manufactured, to provide accurate calibration of a testing chamber. The solar cells can be isolated from environmental attacks, by providing the cover and polymeric layer. A repeatable and desirable amount of power that does not degrade or change over time, can be delivered by the reference module device. Improves solar cell device repeatability, process repeatability, and the cost of ownership of the formation process. A complete solar cell device that can be easily mounted and rapidly installed at a site of customer, can be obtained.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) method of making reference module;    (2) system for qualifying solar cell devices; and    (3) method of qualifying solar cell testing process.    DESCRIPTION OF DRAWING(S) - The drawing shows an isometric view of the reference module device.    Reference module (600)    Sun (601)    Cover (605)    Solar cells (610)    Substrate (615)