Innovation along the PV value-added chain
Since 2009, 28 companies, 9 research institutes and 10 universities of applied sciences and universities - supported by the Federal Ministry of Education and Research (BMBF) and the States of Saxony, Saxony-Anhalt and Thuringia - have processed more than 100 R&D projects with a budget of € 120 million. The results lead to cost reductions on all levels of the value added chain, starting with the silicon as the raw material via the crystals, wafers and cells produced from it through to the module and the complete PV system:
- Silicone: The scientific understanding of silicon has been intensified. As a result of the increase of the detection precision of critical contaminations by a number of orders of magnitude and the development of close-to-industry measurement methods, the process parameters, the check of incoming material and quality assurance have been optimised.
- Crystals: It is now possible to produce outstanding crystals from low-cost solar-grade raw material with float zone methods. Solar cells produced from it show a comparably high degree of efficiency which can otherwise only be achieved by using very expensive electronic-grade raw silicon. The system developed has been designed for mass production. Further applications of these crystals are in the field of high-performance electronics and electro-mobility. In the traditional Czochralski method, the costs can now be clearly reduced, a material design and process management have been optimised on the basis of simulations.
- Wafer: A drastic cost reduction of more than 40% has been achieved in cutting of crystals. This was achieved by introduction of newly structured wires and a new slurry. In addition, highly efficient thin wafers with up to a thickness of 110 µm can be produced. In this way, the amount of material can be clearly reduced.
- Solar cells: New processes (PERC, PERT, IBC, hetero-junction) permit an increase of the degree of efficiency to up to 22%. These are leading edge values worldwide. Thanks to the higher degree of efficiency, the energy generation costs drop distinctly.
- Module: The achieved gain in output and income in cells has successfully been transferred to the modules. Currently, outputs of more than 300 Wp are achieved with this. Module reliability has been distinctly improved. In particular, the potential-induced degradation can be avoided effectively by counter-measures on the cell and module level.
- System: Manufacturers of thin-layer modules have developed specific solutions for building-integrated photovoltaics. These new components take on additional functions of the building shell alongside energy production by being inserted directly into the façade or the roof shell as a construction element. In addition, a module inverter system has been developed, permitting optimum operation of BIPV systems.