Hitachi manufacturers a unique “bifacial” PV cell as well as several bifacial module styles. While most of the PV module manufacturers use monofacial PV cells in their modules, Hitachi has developed a unique high-efficiency cell that can produce power from both the back and front sides of the PV cell.
The amount of power produced from the back-side is dependent on the amount and method of getting sunlight onto the back of the solar cell or module. Until recently, options to accomplish this have been limited to using mirrors or reflectors. New optics and technologies being developed separately by the two companies are providing exciting opportunities to gain improved power production from solar cells.