Solar power is a key puzzle piece in Germany's Energiewende, or transition to renewable energy. Most of today's solar cells are made of crystalline silicon. However, thin-film technologies outperform these conventional cells on several fronts. The CIGS1 materials system's advantages are particularly persuasive, which is why it figures so prominently in ZSW's solar cells and modules.
Stuttgart University led the way in 1989 with solar cells that achieved 17% efficiency over a small surface. ZSW stepped up the research into this promising technology and succeeded in scaling it up for mass manufacturing. Ramping up cells from the lab to the factory floor is not just a matter of extending the surface area many times over. Systems engineering challenge is no less daunting. Perhaps the most difficult task is to scale up semiconductor and contact layer production from a 1 cm² to a 1 m² substrate manufactured on a high throughput, high yield line. ZSW optimized the processes and systems to meet the demands of industrial manufacturing. A pilot phase with Würth Solar followed, after which the comopany started making CIGS solar modules in a 30 MW factory featuring the technology developed at ZSW. Production continued until 2011, after which ZSW's current industrial partner Manz AG bought the factory in Schwäbisch Hall and converted it into a facility for demonstrating its CIGS module manufacturing capability to customers who are interested in its production systems.
Manz AG has cooperated with the Chinese partners Shanghai Electric Group and Shenhua Group since 2016. The company is now building a 44 MW CIGS research line and a turnkey 306 MW CIGS plant (CIGSfab) to mass manufacture CIGS thin-film solar modules in China. Manz AG markets turnkey production lines for manufacturing CIGS modules worldwide. An R&D joint venture founded with Chinese partners in 2016 and including NICE Solar Energy GmbH, the successor to Manz CIGS Technology GmbH, has started research activities in April 2017. This joint venture aims to fast-track the development of CIGS technology in close cooperation with ZSW to harness the potential for boosting efficiency and cutting manufacturing costs.
1 (Cu(In,Ga)Se2 = copper, indium and/or gallium as well as selenium)
Learn more about thin-film tech at Photovoltaics.