Solar Power from Sun and Rain

Chinese scientists develop solar panels that work in sun & rain

Scientists in China are developing revolutionary solar cells that couldtrigger electricity from both the sun and rain.

The scientists Qunwei Tang, Xiaopeng Wang, Peizhi Yang, Benlin He from Ocean University of China in Qingdao and Yunnan Normal University in Kunming developed a highly efficient and flexible dye-sensitized solar cell and then coated that cell with a one atom-thick layer of electron-enriched graphene. Dr Qunwei Tang is a full professor of Materials Science at Ocean University of China. His research is focused on dye-sensitized solar cell and electrode materials for advanced energy conversion devices.


The bi-triggered solar cell was assembled on an indium tin oxide (ITO)-polyethylene terephthalate (PET) substrate by coating a TiO2 anode layer with thickness of around 10 mm, sensitizing with 0.5 mm N719 dye, and an ITO-PET supported Pt (Pt3Ni alloy) counter electrode (CE) for front irradiation and Co(Ni)0.85Se CE for rear irradiation. Subsequently the redox electrolyte having I ¢ /I3 ¢ couples was injected into the interspace between a TiO2 anode and a CE and the solar cell was sealed under hot press.



Figure 1



The final solar cell architectures that can be excited by sunlight and rain are shown in Figure 1 and the Supporting Information, Figure S1.





Graphene layer could allow solar cells to generate power when it rains.

This phenomenon inspired researchers working with Qunwei Tang to use graphene electrodes to obtain power from the impact of raindrops. Raindrops are not pure water. They contain salts that dissociate into positive and negative ions. The positively charged ions, including sodium, calcium, and ammonium ions, can bind to the graphene surface.


Graphene is a two-dimensional form of carbon in which the atoms are bonded into a honeycomb arrangement. It can be prepared by the oxidation, exfoliation and subsequent reduction of graphite. The material conducts electricity and is rich in electrons that can move freely across the entire layer (delocalized). In aqueous solution, graphene can bind positively charged ions with its electrons (Lewis acid-base interaction), a property used in graphene-based processes to remove lead ions and organic dyes from solutions.

The solar cell can be excited by incidental light on sunny days and raindrops on rainy days, yielding a solar-to-electricity conversion efficiency of 6.53% under AM 1.5 irradiation and current over microamps, as well as a voltage of hundreds of microvolts by simulated raindrops.

Note: New Renewable Energy Generator Grabs Electricity from Rain as well.