Could India’s ‘fruit of the gods’ help lower the price of solar cells? Scientists at the Indian Institute of Technology (IIT) Roorkee discovered jamun, a black plum, contains a pigment able to absorb sunlight. They think utilizing the fruit in mass production of solar panels could slash costs.
Jamun, Syzygium cumini, is indigenous to south Asia and is sold on the street for cheap prices. Jamun trees can grow to be nearly 100 feet tall and live for 100 years, and the black plums from those trees are lauded for medicinal and nutritional value. But now they may play a role in generating clean energy as well, thanks to their pigment anthocyanin.
IIT-Roorkee assistant professor Soumitra Satapathi told Quartz India, “We were looking at why the jamuns are black. We extracted the pigment using ethanol and found that anthocyanin was a great absorber of sunlight.” Satapathi and two other researchers from the institute used that anthocyanin as a sensitizer in dye sensitized solar cells (DSSCs). They think utilizing naturally occurring dyes, like the jamun pigment, could lower solar panel costs by 40 percent. Anthocyanin is also found in blueberries, raspberries, cherries, and cranberries.
DSSCs aren’t as efficient as traditional silicon-based solar cells yet, but could offer a low cost alternative – beneficial especially for India as the country aims to gain 40 percent of energy from renewables by 2030. But the IIT scientists aren’t quite there yet; their DSSCs only have an efficiency of 0.5 percent, contrasted with traditional solar cells’ efficiency of over 15 percent.
Nevertheless, the scientists pointed out jamun is widely available, and could offer a biodegradable, non-toxic alternative to synthetic dyes that have been used in DSSCs. The IEEE Journal of Photovoltaics published the research online recently.