In the 21st century, solar technology can be used to power all sorts of things — but only if the sun is shining, of course. Now, a group of Chinese researchers is stretching the boundaries of what we think we know about solar power by developing panels that continue to collect energy even when the clouds roll in.

Solar panels coated with raindrops.For some time, scientists have known that adding a pseudocapacitor or triboelectric nanogenerator (TENG) to an existing solar cell would allow it to register the movement of raindrops as they hit its surface. It’s these same movements that are now being made into energy. Unfortunately, this technology has almost always come with limitations, mainly because the materials involved (especially the insulation) tend to block actual sunlight from reaching the solar cells. This means that its effectiveness was limited to creating energy exclusively from rain, eliminating the panels’ sunlight-capturing abilities altogether. In other words, most solar panels can either collect energy from the rain or from the sun, but never from both.

With this knowledge in mind, researchers Zhen Wen, Xuhui Sun, and Baoquan Sun set out to develop a functioning hybrid device that could absorb energy whether the sun was out or rain was falling.

Solar panels under cloudy skies.

To achieve this goal, the researchers implemented the use of two different polymers: PDMS (polydimethylsiloxane) and PEDOT:PSS (poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate)). After a little trial and error, they eventually found that the PDMS increased the performance of the TENG whenever water hit and bounced off the cells. The PEDOT:PSS was then placed between the TENG and the cells, where it worked as a conductor to transfer energy between the two. The key factor in this design is the polymers’ transparency, which allows them to draw energy from the rain without blocking the cells off from sunlight.

With any luck, these hybrid solar panels will be hitting the market soon. However, they are still decidedly in the developmental stage, with the researchers working hard to improve their overall efficiency. When they are ready, they’ll be opening up the solar option to a ton of people who have never been able to run their homes using traditional panels because of the climate in their areas.

Although the up-front cost of solar panels is a bit of an investment, the long-term payoff is lower (if any) power expenses. Expanding this option into a hugely untapped market will finally give the entire world the opportunity to take advantage of these savings and cut ties with the electric company once and for all.