Study claims perovskite solar cells can recoup their energy cost within three months

Scientists at Northwestern University and the U.S. Department of Energy have found that perovskite cells, one of the most promising solar technologies of recent years, can repay their energy cost over 10 times faster than traditional silicon-based solar cells.
The finding confirms that, once issues related to cell longevity are ironed out, perovskite cells could soon bring us solar energy on the cheap, and do so with less impact on the environment over their lifetime.
Solar panel installations are doubtlessly having a positive impact on the environment, but quantifying their carbon footprint with some degree of precision, which is useful for comparing them to other means of energy production, including other renewables, is not a straightforward process. To get a more complete picture, it’s important to consider not only the carbon emissions saved during the panel’s operating life, but also the amount of energy that goes into materials processing, manufacture, repair, maintenance and, once it is no longer useful, disposal of the panel.
According to this metric, called the cradle-to-grave life cycle assessment, a typical solar panel takes a fairly long time, between two and three years, to offset the energy costs that went into producing it. This is because silicon-based solar panels must be manufactured inside a clean room using high-purity crystalline silicon wafers that can only form inside specialized high-temperature furnaces.
Scientists at Northwestern University have now calculated that, by contrast, perovskite-based solar cells have an energy payback time (EPBT) of only two to three months. According to the researchers, this is not only much faster than a silicon-based cell, but also significantly better than any other type of commonly available solar cell.
Perovskite cells are the fastest-growing technology in the solar arena. Although they aren’t quite as efficient at converting sunlight into electricity as silicon-based cells, they are catching up very quickly. More importantly, they are much cheaper to produce than normal panels, meaning that their commercialization could lead to a drastic drop in the cost of clean electricity.
Because of their very short lifetime, the researchers found that the overall CO2 impact of perovskite cells is still significantly higher than that of traditional silicon-based cells, which are much more durable with a reported average lifetime of approximately 20 years.
But if these issues are solved (which the researchers say could happen in as little as two years), perovskite cells could indeed rise to take the lion’s share of the solar landscape in the near future, providing clean energy while having an even lower impact on the environment than the solar cells of today.