Photovoltaic modules based on perovskite-silicon tandem solar cells could be produced in the United States at a minimum sustainable price of $0.35/W, according to a techno-economic analysis conducted by researchers from the US Department of Energy's National Renewable Energy Laboratory (NREL).
“Our work is based on data we collected from equipment manufacturers and material providers in the past year,” the research's lead author, Jacob J. Cordell, told pv magazine. “We assumed the modules to have an efficiency ranging from 25% to 35%.”
The data were processed through the detailed cost analysis model DCAM, which is an open-access tool developed by NREL itself for
building cost models for PV components and systems. The calculation of the levelized cost of energy (LCOE) was made assuming tandem efficiencies of up to 35%, lifetimes ranging from 10 to 30 years, and GW-sized factories.
The researchers provided a detailed techno-economic analysis of both two-terminal (2T) and four-terminal (4T) solar cell architectures and said that, despite their potential multiple design configurations, they face similar manufacturing costs. The 4T designs, however, may be preferred in the future, as the 2T configuration excludes the use of back contact (BC) devices for the bottom cells. On the other hand, high-efficiency technologies as BC and heterojunction (HJT) could be the preferred choice for tandem modules, which are mainly designed to maximize efficiency and power generation. Their analysis, however, also included PERC and TOPCon technologies.
The research team found that, without the policy incentives awarded by the Inflation Reduction Act (IRA), 25%-efficient perovskite silicon solar modules could be currently produced in the United States at $0.359/W for 4T designs and $0.364/W for 2T architectures. It also ascertained that, with a 30% efficiency, 4T panels may be manufactured at $0.299/W and 2T modules at $0.303/W.
“At 32.5% module efficiency, the 4T cost drops below our modeled cost for a 22%-efficient PERC Si module cost, $0.285/W,” it further explained, noting that, with a 35% efficiency, the cost would range between $0.257/W and $0.306/W.
Solar glass, backsheets, encapsulation, and electron transport layer (ETL) precursors in the perovskite sub-cell are responsible for the tandem modules' higher costs compared to single-junction products, according to the scientists, due to the materials and equipment needed.
The academics believe these costs may be further reduced in the near future, as they expect costs for silicon cells to further drop, while perovskite precursors and processing equipment may become more industrially standard.
According to Cordell, however, perovskite-silicon tandem modules may reach commercialization only with a proven track record of their performance. “We have seen recent perovskite-based PV plants come online in China and if data from these facilities will be made available, we may have some interesting information about degradation over time,” he said. “A 2-year testing in combination with accelerated testing may help this technology come closer to the market.”
Cordell also said it is difficult to evaluate how much data is needed. “Of course, selling a product doesn't need necessarily increasing market shares,” he stated. “It may take longer than expected to reach this goal, as other degradation mechanisms may emerge, as we are seeing for TOPCon modules right now in the field.
The NREL scientists added that, even considering the costs of silicon PV manufacturing in China, tandem modules may find it hard to compete with single-junction counterparts, as commercially available TOPCon, BC, and HJT cell efficiencies keep increasing and costs continue to drop. “However, our assumptions were based on a type of manufacturing equipment that doesn't exist yet,” he said. “If the tandem modules' costs are high right now, it doesn't mean it will be the case in two years. A larger perovskite industry may contribute to changing this picture.”
Cordell also stressed that tandem modules will also offer an advantage in terms of efficiency per area. “It is not only about the cost per watt,” he said. “Lowered costs that you don't have to buy or lease should more land should then also be factored in. This technology will be mostly developed with large-scale projects, at least initially.”
The research work was presented in “Technoeconomic analysis of perovskite/silicon tandem solar modules,” published in Joule.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.
By submitting this form you agree to pv magazine using your data for the purposes of publishing your comment.
Your personal data will only be disclosed or otherwise transmitted to third parties for the purposes of spam filtering or if this is necessary for technical maintenance of the website. Any other transfer to third parties will not take place unless this is justified on the basis of applicable data protection regulations or if pv magazine is legally obliged to do so.
You may revoke this consent at any time with effect for the future, in which case your personal data will be deleted immediately. Otherwise, your data will be deleted if pv magazine has processed your request or the purpose of data storage is fulfilled.
Further information on data privacy can be found in our Data Protection Policy.