Manufacturing Laminate-Free PV Modules at Large Scale

Abstract

As photovoltaic (PV) technology enters the terawatt era, reliability, sustainability, and circularity in the solar industry can no longer be optional considerations for manufacturing solar modules. Despite two decades of intense solar manufacturing, the PV industry still predominantly operates within a linear economic structure, characterized by energy-intensive production and limited sustainability practices. One significant challenge associated with crystalline PV modules is the encapsulation process, which occurs within costly and unwieldy laminator machines. While laminating PV modules offers long-term stability and performance, it also imposes significant limitations on the disassembly, repairability, and recyclability of valuable PV module materials. The development of sustainable PV designs and manufacturing processes is crucial for transitioning to a circular economy. In response to this problem, Biosphere Solar, a startup company based in Delft, is developing a novel solar module design that eliminates the need for lamination. Their focus is on creating an easily disassembled solar module to facilitate repair, reuse, and ultimately achieving full recyclability with low-energy input. It is crucial to recognize that transitioning to non-laminated modules presents challenges in manufacturing. This thesis aims to identify and address barriers encountered in manufacturing laminate-free PV modules compared to traditional PV panels. First, becoming acquainted with laminated PV lines provided insights into the challenges to be encountered. The analysis of the laminate-free product primarily examines the module components, and materials diverging from laminated panels, such as adhesives, solder pastes, fillers, and edge sealants, assessing their trade-offs and configurations in terms of manufacturability. The product analysis has facilitated the definition of a manufacturing process flow, which is constructed based on assembly operations that both align with and diverge from standard PV manufacturing practices. This is complemented by an exploration of non-standardized processing methods, considering the associated boundary conditions in the assembly. The main challenges encountered include the metal paste dispensing, low-temperature soldering, and fluid filling processes, with multiple units installed and a necessity for a specific design tailored to this application. This study demonstrates competitiveness with respect to laminate PV line scales, particularly evident in larger-scale operations. Technically, a 30% reduction in energy consumption for machinery and up to 50% factory area savings can be achieved. The electrical consumption of the laminator(s) alone, for production volumes up to 300MW, can range between 20% and 50%, with a footprint share of up to 10% of the total manufacturing space. Economically, capital costs also demonstrate promise and have the potential to outperform laminated PV modules, especially in a highly automated setup line. Savings between 20-30% for equipment costs and up to 50% for building infrastructure costs are achievable. Nevertheless, the main factors offsetting these mitigated capital costs are the operational expenses associated with the bill of materials and the manpower required to produce this specific product. These material expenses can be up to 4-5 times higher than for a laminated panel, and up to twice the investment in manufacturing labour. This assessment lays the foundation for future research leveraging the trade-offs explored to refine choices and achieve optimal results.