Project Name: Monolithic Silicon Module Manufacturing at Under $0.40 per Watt
Funding Opportunity: PVRD
SunShot Subprogram: Photovoltaics
Location: Tempe, AZ
SunShot Award Amount: $800,000
Awardee Cost Share: $88,886
Project Investigator: Zachary Holman
This project aims to lower the cost of photovoltaic (PV) electricity generation in fewer than five years to $0.04 per kilowatt hour through the development of a PV module that is based on back-contact silicon solar cells, which have interdigitated metal fingers on their rear sides and no metal on their front sides. The cells in this project will not have any metal; instead, they will be interconnected with a “flex-circuit” consisting of two layers of aluminum foil separated by an insulating spacer layer. This design reduces the amount of silver or copper used in modules and eliminates solder points that are prone to failure. This project will focus on cell interconnection, module assembly, module reliability testing, and techno-economic analysis.
The research team is working to develop a symmetric glass-glass module with a dual-layer aluminum flex-circuit bonded to back-contact silicon solar cells. The project will include flex-circuit design and the testing of cell connection, module assembly, and module reliability to demonstrate a 60-cell module with efficiency greater than 22% at the projected manufacturing cost of less than $0.40 per watt. The technology will be developed with the goal of mass production in under five years. In addition, the team will conduct ongoing techno-economic analysis to ensure that the developed technology meets the demands of the evolving the solar market.
The module design proposed in this project is unique because it enables cost savings at the cell, module, and balance-of-systems levels of the PV value chain. The key innovation of the project is the replacement of silver grids and soldered tabs with aluminum flex-circuits, decreasing module cost and eliminating a major module failure mechanism. In addition, moving to glass-glass packaging will reduce degradation and allow for inexpensive, high-voltage inverters. Furthermore, because the technology integrates proven components, it is expected to reach mass production in fewer than five years, pushing photovoltaics well past SunShot’s 2020 goal of $0.06 per kilowatt hour by approximately 2022.