The Photovoltaics market has been driven in the last decade by strong increase of module production per year, with > 50 GW in 2015 and predictions for 100 GW after 2020. State-of-the-art products demonstrate efficiencies of 17–18 % and 19–20 % respectively, while increasing market share of high performance silicon technologies are expected, targeting the competitive production of > 22.5 % cells. In that respect, the Silicon Heterojunction Technology (HJT) developed and matured in Switzerland by Meyer Burger is of key relevance, owing to its high conversion efficiency achieved with limited number of production steps (a pre-requisite for keeping reduced costs). In this context, the Swiss- Inno HJT project focused on the demonstration at the pilot scale of cost-competitive manufacturability of high performance silicon solar cells, modules and systems, based on the key processes and technologies expertise of the Meyer Burger group and of CSEM, with the objective to transfer this high power output technology with low production costs to the photovoltaic market.
Pilot lines were installed and ramped-up for HJT cells manufacturing, with innovations conducted at material, processes and design levels. The project enabled going from 21 % cell efficiency using lab-tools to 22.2 % average efficiency achieved with Meyer Burger mass-production equipment, and with efficiencies up to 22.8 % achieved with CSEM metallization R&D pilot line. This was achieved on bifacial cells and with > 30 % cell manufacturing costs reduction (only 0.4 CHF/wafer for the last cell generation). These achievements in a mass-production relevant environment demonstrate the feasibility of manufacturing high efficiency HJT cells at extremely competitive costs. The innovative SmartWire module technology was demonstrated to enable for high performance, with 330 Wp record module. Two generations of modules were manufactured in 2016 using bifacial heterojunction cells produced in the pilot lines, showing performance in the 300 Wp range, with potential for enhancement to 310-320 Wp class based on the achieved cell efficiency and module developments. The third module generation demonstrated materials cost reduction enabling to achieve down to 40 CHF/module. The cumulated wafers, cells and modules costs using technologies demonstrated in this project result in a minimum calculated cost of 0.41 CHF/Wp for the demonstrated silicon heterojunction technology, achieving strong reduction in comparison to the initial project targets, enabling for high competitivity. Finally, two-monitoring sites were completed in the project, with the 3 generations of produced modules installed on the publicly visible site next to the port and Latenium site in Hauterive, NE. The modules were successfully installed and performance monitoring initiated. First data collected indicate performance ratio potential for the developed technology in par with the project targets of > 91 %. The data analysis typically requires averaging of 1-year data for reliable performance analysis, and will be finalized therefore for the second and third generations of modules in the course of 2017.
The project achievements provided high visibility of the outstanding results achieved in Switzerland on these technology developments. The pilot lines enabled for acceleration of the developments for competitive HJT cells manufacturing, and for demonstration to potential clients. First industrial projects for silicon heterojunction cells manufacturing could be concluded by Meyer Burger in Europe, Russia and Asia. The Meyer Burger Silicon HJT technology is today further placed on the roadmap of most of the cells manufacturers worldwide. The remaining hurdles for wider integration are today linked to the initial CAPEX expenditure to be realized. Further developments in that direction will be key to achieve full industrial success.
