Raindrops may help power the next-generation solar panel

By Kelly Hodgkins April 10, 2016

chile solar energy here s how many panels we d need to provide power for the entire planet — Pedrosala / Shutterstock

Solar technology has improved gradually over the past decade with most of the advances focusing on extracting as much energy out of sunlight as possible. A group of researchers from China, however, has tackled another problem with solar power — generating power during periods of clouds and rain.

Scientists from the Ocean University of China (Qingdao) and Yunnan Normal University (Kunming, China) have created an all-weather solar cell that works both in the sun and in the rain. The technology takes advantage of the unique qualities of graphene, which allow it to produce energy from, believe it or not, raindrops.

Like most solar panels, the new solar cell can generate energy from sunlight on sunny days using existing technology. When the clouds roll in and raindrops start to fall, the solar cell then can switch to its graphene-based energy collection system. The critical component in the rain-based system is an aqueous form of graphene. Liquid graphene can conduct electricity due to its delocalized electrons that help set up a pseudocapacitor that can be used in the generation of electricity.

When rain drops hit the graphene-containing solar cell, the rain is dissociated into positive and negative ions. These positive ions are primarily salt-related ions, such as sodium, calcium, and ammonium, that accumulate on the graphene surface. This positive layer interacts with the negative electrons in the graphene to create a dual-layer system that acts like a pseudocapacitor. The difference in potential between the two layers is significant enough to produce voltage and a current.

Researchers hope to move their research beyond a proof of concept stage and begin to develop the technology into a viable method for generating electricity. These all-weather cells would provide a boost to solar cell technology which currently only works when there is ample sunlight. In climates or seasons that are dominated by clouds and rain, an all-weather solar panel could provide a clean form of energy that is not possible with existing technology.

Editors' Recommendations

Topics

Contributor

Kelly's been writing online for ten years, working at Gizmodo, TUAW, and BGR among others. Living near the White Mountains of…

Mobile

Qualcomm’s X60 5G modem will power the next generation of 5G flagship phones

qualcomm x60 5g modem news

Qualcomm is bringing the 5G connectivity in today's phones to the next level: The company has announced the new Qualcomm X60 modem, which Qualcomm says will help bring 5G into the mainstream through a new generation of flagship smartphones.

5G in general is likely to take off in 2020. Carriers including Verizon, AT&T, and the new T-Mobile/Sprint are finally widely rolling out their 5G networks, and smartphone manufacturers like Samsung are beginning to build 5G into their smartphones by default -- rather than offering a special 5G-enabled version of a device that costs a lot extra.

Emerging Tech

Semitransparent solar cells could power tomorrow’s self-sustaining greenhouses

Solar cells on top of greenhouses.

Most people understand the broad principles of a greenhouse: A greenhouse is a building with a glass roof and walls, used to grow plants like tomatoes and tropical flowers. The greenhouse stays warm inside, even during night and the winter. That’s because the glass walls of the greenhouse trap the sun’s heat inside. So far, so great.

But what if greenhouses could be used not just to help plants grow, but also to capture light at wavelengths that plants don’t use -- all thanks to some smart semitransparent solar panels built into the greenhouse walls themselves. Among other uses, these could help to make large commercial greenhouses entirely self-sufficient.

Emerging Tech

New ‘reverse solar panel’ generates power at night by radiating heat into space

Solar panel at night 1

For obvious reasons, today’s sun-powered solar cells don’t work at night. But researchers from the University of California, Davis believe that they may have come up with a solution. And it’s one that would allow specially designed photovoltaic cells to keep generating power even when it’s dark. While this would only be around a quarter of what a regular solar panel is able to generate during daytime, that would nonetheless be a quarter more power than is currently generated at night.

The approach works a bit like a regular solar cell in reverse. A conventional solar cell is cool compared to the sun, so it absorbs light. But if you take a warmer object and point it someplace cold it will radiate heat toward it in the form of infrared light. That’s what the UC Davis researchers have been doing, directing their solar cells at the sky, where it will radiate infrared light because it is warmer than outer space. Due to some smart physics and a device called a thermoradiative cell which generates power by radiating heat, they believe they may have come up with a breakthrough type of solar cell.