Economic evaluation of two-step metallization processes for silicon solar cells
Two-step approaches for front side metallization of silicon wafer solar cells are evaluated regarding their economical properties. The efficiency advantage of such processes is determined in two experiments and translated into an economical advantage using data from latest publications and present module spot market prices. Process costs are estimated based on ISEs extensive data pool and experience with processes. Material usage is varied to reach the economic optimum. An efficiency advantage for the two step approach, compared to standard screen printing, of 0.4 %abs with a very conservative process is demonstrated. An adapted process should give an even higher gain. Even for conservative assumptions, cost-effectiveness for the two-step approach is found. Furthermore the flexibility of process approaches with plating as second step is illustrated. Implementation possibilities of two step metallization processes in industrial production lines are discussed. An addition al calculation replacing silver with copper shows an even higher economic potential for future metallization solutions. A roadmap comprising several milestones for a stepwise reorganization of industrial solar cell metallization is proposed.