Solar Energy, Even When It Rains? Chinese Scientists Could Make It Happen

It’s hardly considered illogical to associate solar power with Sun-based energy. Although panels do continue to harvest solar energy during rainy or cloudy days, scientists were stumped for a considerable amount of time as to how to maximize green energy when it rains.

According to Science Daily, Chinese scientists at the Ocean University of China in Qingdao and Yunnan Normal University in Kunming may have found a groundbreaking solution.

“For the conversion of solar energy to electricity, the team from the Ocean University of China (Qingdao) and Yunnan Normal University (Kunming, China) developed a highly efficient dye-sensitized solar cell. In order to allow rain to produce electricity as well, they coated this cell with a whisper-thin film of graphene.”

Graphene is, as Science Daily writes, a “two-dimensional form of carbon in which the atoms are bonded into a honeycomb arrangement.” This unique substance, something RT referred to as a “wonder material,” was discovered only about a decade ago. Since then, scientists have been working to apply its properties in various ways, including usage for upgrading solar energy technology.

Researchers have long believed that rain water had other energy uses for solar energy panels aside from just keeping them clean. The challenge was finding a viable method of application. Now it’s believed that graphene layers on solar panels could cause a unique “chemical reaction” when it rains that would harvest additional energy.

Business Insider explains it as scientists wanting “to use graphene sheets to separate the positively charged ions in rain (including sodium, calcium, and ammonium) and in turn generate electricity.”

The key to this theory is the fact that rainwater is itself not pure water; these positively charged ions from non-water materials like sodium and ammonium would be what researchers would hope to use to create “electric rain.”

While the concept seems incredible, the experimental panel made by scientists at the Ocean University of China and Yunnan Normal University have reportedly produced some very promising results.

RT writes that to determine if this theory was possible, a “cheap thin dye-sensitized solar cell” was used, featuring a “thin layer of graphene on top.” Both items were “then placed atop a layer of indium tin oxide and plastic.”

“The positively-charged ions then interact with the graphene, producing a double layer that contains the electrons. Now this top double layer begins to interact with the negatively-charged ions in the layer below. The charge difference between them is enough to create an electrical current.”

“Slightly salty water” was then poured over the experimental solar cell — a simulation for rain.

The outcome of the experiment, as reported by RT, was that researchers “achieved 6.53 percent efficiency during conversion from solar to electric power.” They also “produced hundreds of microvolts.”

For the sake of clarity, it’s important to note that this is “proof of concept.” That means the research proves that rainwater could be used to gather additional green energy from solar panels. It also shows that graphene could very likely be the key to making that happen. However, there are still many steps to take before scientists can claim to have created a new type of solar panel capable of generating electricity when it rains and by strictly using rainwater.

The good news is that Ocean University has reportedly already begun taking steps to “refine the process.”

“The team is now analyzing rain water to uncover the variety of ions it contains and put them to use. This is not easy as they’re normally found in quite low concentrations, but progress is certainly being made.”

In addition to using graphene to get the most out of the rain, it’s reported that earlier this year, British scientists made significant strides towards using graphene, which readily absorbs “ambient heat and light,” to create solar panels specifically for sunlight that “finds its way indoors.”

Whether sunny or rainy, it’s fair to say the future of solar energy is looking increasingly bright.

[Photo by Mark Lennihan/AP Images]