SCHOTT Solar, the solar manufacturer based in Mainz, Germany, pushes the peak efficiency of polycrystalline solar modules to new heights once again. The ESTI (European Solar Test Installation) in Ispra, Italy, confirmed previously unseen record efficiency of 18.2 on the aperture area after performing its own independent measurements. This achievement is based on the high-performance cell technology with which SCHOTT Solar had already secured itself the world record for efficiency in September 2010. Since then, the German company that specializes in solar energy has continuously improved this technology – and thus made yet another valuable contribution to making power from solar systems more affordable and therefore more competitive in the future. SCHOTT Solar will be presenting its latest innovations at the EU PVSEC in Hamburg from September 5 – 9, 2011 (hall B5, booth A37).
Thanks to intensive research efforts, SCHOTT Solar has succeeded in further developing the processes at the wafer, cell and module level quite considerably. “This is the result of an integrated research performance on the behalf of the entire SCHOTT Group,” emphasizes head of development, Klaus Wangemann. For instance, its subsidiary SCHOTT Solar Wafer GmbH in Jena has managed to improve the electronic quality of its silicon wafers. This can be attributed to the further improvement of the company’s crystallization technology. Development at SCHOTT Solar AG in Alzenau, on the other hand, has reengineered its cell and module concept. The new cells are connected by three interconnectors that allow for reduced electrical losses. Furthermore, the new, so-called in-line diffusion process developed by SCHOTT Solar is being put to use on the front side. This, in turn, allows for long diffusion times with throughputs of around 3,200 wafers per hour and thus forms the basis for putting high-efficiency concepts into practice in the future.
The back side, on the other hand, features a so-called PERC structure. In other words, it has been passivated using a combination of various dielectric layers and equipped with local contacts. These contacts are applied using conventional screen printing technology.
SCHOTT Solar uses 60 of these high-performance cells with efficiency of up to 18.7 percent in its new record-breaking module. This has resulted in a new independently confirmed world record for efficiency of 18.2 percent for polycrystalline modules with respect to the aperture area.
On the way to practical application – Claim to leadership confirmed
All of the individual processing steps involved in the record-breaking module have been industrially tested and are already being used in manufacturing. “We will transfer the entire process over to a mature production sequence rather swiftly,” head of development Wangemann says.