How Do Solar Cells Work Underwater?

Although the power generation of solar cells will be greatly reduced when placed underwater, this is not without benefit to the research on this subject. Researchers in India said that solar cells placed in water can be used to monitor sensors, which can be used in commercial and defense fields.

Scientists at Bura Institute of Technology, Indian Institute of Technology, and Indian Defense Materials Research and Development Institute at the Pirani-Hyderabad campus said that Panasonic’s amorphous silicon battery was used as the test object, and the solar battery immersed in water was relatively in A lower temperature is an ideal clean environment. However, the solar radiation received in the water is significantly reduced. When citing another study, the team of scientists stated that the conversion efficiency of monocrystalline and polycrystalline silicon cells will drop by 20% when under water at a depth of 1 meter, but amorphous silicon cells The conversion efficiency is less reduced at a depth of 1.5 meters. This comparative data is exciting: the remaining conversion efficiency is enough to power underwater electronic devices.

Scientists tested an amorphous silicon cell at a depth of 20 cm. The surface of this cell is coated with polydimethylsiloxane (PDMS). PDMS is the most widely used silicon-based organic polymer in optoelectronic applications. Things. According to the researchers, PDMS has excellent optical properties and hydrophobicity. "This is an inert, non-toxic, non-flammable polymer", this coating method increases the cell power by 2.79%.

The research team chose amorphous silicon cells because they have the spectral sensitivity to absorb light, and the visible wavelength range of light is basically between 380-780 nanometers. Researchers say this makes amorphous silicon cells an ideal choice for underwater environments. In water, as the depth increases, the spectrum becomes narrower, and longer wavelengths penetrate at the initial depth. In fact, the use of amorphous silicon cells in indoor and outdoor applications has long been commonplace.

When using the SS50AA photovoltaic simulator to test the performance of Panasonic batteries, the batteries were immersed in water in four environments: deionized water, lake water, sea water, and made of purchased sea salt containing 3.5% salinity and other water impurities. Artificial sea water. After experimental comparison, the performance of the Panasonic battery in lake water is the worst. Bacteria, algae and other impurities reduce the transparency of the liquid. The best output power is 0.0367 W, which is the data obtained when the depth of deionized water is 2 meters, and when sea water and artificial sea water are at the same depth, they are 0.0337 W and 0.0320 W, respectively.

"Although there are still many challenges and limitations, the results obtained so far show that photovoltaic power generation technology has great potential in underwater monitoring sensors or equipment, and various other commercial and defense applications of modern power electronics. "The researchers wrote in the article that this study was published in the International Energy Research Journal under the title of "Analysis of Solar Irradiation Results of Amorphous Silicon Solar Cells in Different Underwater Environments."

Sanket Goel, the coordinator of this research and a professor at the Birla Institute of Technology and Science (BITS-Pilani), said, “This research is funded by the Indian National Defense Laboratory and is mainly for exploring and optimizing the use of underwater solar energy. To operate various underwater sensors and monitoring equipment.” This research opens up new directions for the application of solar energy under water.