Specific PVMAT R&D on Siemens CZ silicon product manufacturing

Work at Siemens Solar Industries in manufacturing cost reduction has shown highly leveraging benefits in producing thinner solar cells, larger area solar cells, and introducing back surface field processes which increase efficiency. About half of the cost to produce a solar module is incurred by the time a wafer is produced, and another 20% is added in the cell processing steps. In large area wafer and cell production, the manufacturing costs are almost linearly reduced by increasing the area of the wafer, this benefit is compounded as the wafers are made thinner. Siemens Solar Industries has studied, developed and piloted processes for 250 micron thickness cells, in both 103 mm cell and 150 mm sizes. SSI has also started the development efforts for increasing cell size to 200 mm diameter. The benefit can be a cost reduction as high as 25-30% on the $/Watt production level. Implementation in manufacturing is the key driver for success in achieving this cost reduction potential.