In addition to silicon wafers, silver is a crucial PV panel material carrying electricity from solar cells. However, silver is a precious metal. A study discovered that the fast-growing solar industry could exhaust most of the world’s silver by 2050, where solar businesses will need 85% of global silver reserves.
To achieve net-zero emissions, governments worldwide have been striving to transition from fossil fuel to renewable energy, with solar capacity expected to leap from 1 TW in 2022 to 15–60 TW in 2050. This indicates that the demand for silver will soar, as a study from University of New South Wales in Australia revealed a learning rate of 20.3.
Although a solar cell only comes with a few milligrams of precious metals, many little makes a mickle. The study pointed out that cell manufacturers should largely reduce the use of silver in products to prevent supply woes. Particularly, new technologies including n-type cells demand for much more silver compared with conventional PERC cells.
Academia and the solar industry have been endeavoring to develop solar cell technologies requiring less silver or using copper instead. Despite being a little less conductive, copper actually ranks second only to silver among all known metals. Moreover, copper is more abundant in the crust with a much lower cost (around 1% the price of silver). Australian startup SunDrive has already started to develop new copper slurry as a substitute of silver. Last year, the company achieved 26.41% efficiency using its copper-based solar cell.
However, the research team indicated that the said efforts might not be sufficient. Because the solar industry is transitioning to TOPCon, SHJ and other high-efficiency technologies, silver demand will continue to grow, posing price and supply risks. The team also suggested that copper plating is actually a promising solution that can reduce the amount of silver used and overcome printing-caused physical constraints.
In the coming years, recycled PV panels will constitute a critical silver source. However, more data and research are required as annual volumes of recycled silver will not reach the contribution margin of new silver until decades later. The UNSW study further specified that since the most abundant silver reserves have been mined, developing new silver mines is not recommended as it indicates the requirement of deeper excavations and possibility of extracting low-quality ores, which will both add up energy consumption.
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