A new study analyzed various methods for manufacturing a tandem solar module, comparing the sensitivity of production costs related to materials, equipment, factory location, and other significant factors
What Efficiency Do Perovskite/Si Solar Panels Need to Be Competitive?
Factory productivity and panel efficiency are the two most significant factors influencing the production costs of tandem photovoltaic modules, according to a new sector analysis by the National Renewable Energy Laboratory (NREL) under the U.S. Department of Energy. Researchers Jacob Cordell, Michael Woodhouse, and Emily Warren identified pathways for perovskite/silicon tandem photovoltaics to achieve cost competitiveness with traditional solar modules.
For the U.S. solar industry, this is a significant step forward. Tandem technology offers higher energy yields than single-junction counterparts, increasing solar energy adoption potential. However, it remains a niche market due to existing challenges.
Small-scale prototypes (<1 cm²) have demonstrated efficiencies exceeding 30%, surpassing traditional technologies. Yet, scaling these efficiencies to standard panel sizes (~2 m²) remains a hurdle. Despite investments from hundreds of companies, research institutions, and governments, few functioning tandem photovoltaic modules larger than 1 m² exist today.
The Main Challenge: Reliability
Extending the lifespan of these panels beyond 20 years and understanding the degradation mechanisms behind efficiency loss over time are critical hurdles. Additionally, the economic potential and steps required to make tandem modules economically competitive are areas that demand further exploration.
Analyzing the Production Costs of Tandem Photovoltaic Modules
To bridge these knowledge gaps, NREL researchers used the Detailed Cost Analysis Model (DCAM), a cloud-based tool designed to calculate production and system installation costs. Drawing on data from laboratories, equipment manufacturers, and material suppliers, the team analyzed various fabrication methodologies, comparing production cost sensitivities based on materials, equipment, factory location, and other critical factors.
The findings highlight that factory productivity and panel conversion efficiency have the greatest impact on production costs.
“One of the questions this paper answers is, what is the efficiency value required for competitiveness?” said Cordell.
The study determined that tandem photovoltaic modules must achieve at least 25% efficiency to compete on price with other solar technologies.
Key Findings on U.S. Production Costs
In the U.S., for a factory producing 3 GW of solar panels annually, the minimum sustainable price for a two-terminal tandem module with 25% efficiency is $0.428/W. For a four-terminal architecture, the cost decreases slightly to $0.423/W.
Interestingly, doubling factory production yields the same cost reduction as a 2.5% increase in module efficiency.
Next Steps for Tandem Photovoltaic Modules
To commercialize perovskite/silicon tandem modules, the focus must shift to improving field reliability and scaling high-efficiency device areas to full module sizes without sacrificing performance.
The findings were published in the scientific journal Joule.
