With countries increasingly turning towards renewable energy in recent decades, scientists across the globe are looking for more efficient and cheaper ways of harvesting it on a large scale. As part of a new research, a team from Shandong-based Ocean University of China is developing graphene-fitted solar panels that can capture usable energy from raindrops.
Despite its myriad advantages, solar power has its own set of drawbacks, including its unavailability at night as well as on cloudy days. Therefore, photovoltaic cells are never actually used to their fullest capacity. A team of Chinese researchers has proposed an incredibly innovative solution, in the form of a special graphene-fitted solar panel that is capable of producing energy every time it rains.
As the scientists point out, raindrops are not pure water, and usually contain a variety of salts that can be broken down into positive and negative ions, via a simple chemical reaction. With the help of specially-designed graphene sheets, the team has been able to disintegrate rainwater, using the positively-charged ions (such as calcium, ammonium and sodium) to generate electricity.
For the research, recently published in the Angewandte Chemie journal, the scientists worked with dye-sensitized solar cell, a type of thin-filmed PV cell that is inexpensive and also easily available. To this, the team added a single sheet of graphene, covering it with a transparent layer of indium tin oxide and plastic. The newly-developed “all-weather” photovoltaic panel, according to the researchers, is capable of harnessing power from sun’s rays as well as rain.
This is mainly because of the ability of graphene to bind with the positive ions, thereby forming two layers of electrons known as pseudocapacitor. The resultant difference in potential energy between the two layers is what generates the electric current. Using salt-infused water to simulate rain in the laboratory, the researchers were able to produce hundreds of microvolts of electricity, at a conversion efficiency of around 6.53-percent.
Although still in the early stages of development, the breakthrough could revolutionize the renewable energy industry. At present, the team is trying to alter the properties of the graphene-fitted solar cells, so that they can easily react with the variety of ions present in rainwater. Furthermore, the technology needs to be efficient enough to be able generate adequate electricity from the low concentrations of ions typically found in raindrops.