Honda Motor Co. recently announced plans to begin mass production in 2007 of an independently developed thin-film solar cell composed of non-silicon compound materials, which requires 50% less energy, and thus generates 50% less CO2 during production compared to a conventional solar cell. A 12,000-sq m mass production plant with an annual capacity of 27.5 MW will be established at Honda’s existing Kumamoto factory.
Honda initially will produce and sell solar panels in Japan, starting in the fall of 2006, using an assembly line within Honda Engineering, the production engineering subsidiary of Honda. It is looking at overseas markets for the future, however. The cells are intended for individual residential and public industrial applications.
Thin-film solar cell manufacturing differs from silicon crystalline manufacturing, in which molten silicon is processed into solar cells. Thin-film manufacturing involves the application of chemical layers to a substrate. After the layers have been processed, the substrate can be partitioned into individual cells.
While thin-film solar cells have generally had lower efficiencies than crystalline cells, they also have had significantly lower manufacturing costs. However, Honda’s new solar cell has achieved a high level of photoelectric transfer efficiency for a thin-film solar cell—an increase of approximately 20% compared to amorphous silicon cells. According to David Iida, PR spokesperson for Honda, the estimated module photoelectric transfer efficiency for the new solar cell is 12%.
By using a thin-film compound of copper, indium, gallium and selenium (CIGS), Honda’s solar cell reduced the energy consumed during solar cell production to approximately half that required to manufacture conventional crystal silicon solar cells. Thus, this new solar cell is more environmentally friendly by reducing the amount of CO2 emitted during its production.
Since spring 2002, Honda has been using and monitoring the performance of this solar cell, first at the Outboard Engine Plant in Hosoe and then at 12 other Honda facilities, including Honda Engineering headquarters and the Honda Wako Building in Japan as well as overseas sites in the United States and Thailand.
Achieving lower costs and higher photoelectric transfer efficiency is required to expand use of solar cells. This non-silicon thin-film solar cell has been attracting significant attention as a potential solution to this challenge. The only remaining challenges were the stabilization of performance and development of mass production technologies. Mass production of the solar cell became possible with a new mass production process for thin-film solar cells developed independently by Honda Engineering.