Falling water holds a lot of power, as any 18th-century mill operator knew. For some time, scientists have been trying to figure out how to capture the power of falling raindrops to generate electricity.

A key problem has been integrating all of the tiny amounts of power generated by each individual drop into a meaningful electric current—a problem a team of Chinese and U.S. scientists claim to have solved.

When a raindrop falls on the surface of the researchers’ collection panel, the drop takes on a positive electric charge and the surface itself becomes negatively charged. Those individual tiny charges are each collected by a “nanogenerator” under the panel’s surface.

However, the attempt to use standard circuitry to gang the tiny generators together wasn’t working here the way it does in solar panels; for some reason, there was an unintended electrical interplay between components that reduced the panels’ output. That doesn’t happen with solar panels.

On an inspiration, the engineering team switched to something called “bridge array generators” to keep the little generators from interfering with each other and maintain the full amount of current collected. That boosted the amount of current the panel delivered.

They also discovered that the thickness of the collection panel itself was key.

Making the panel thicker helped reduce the electrical interplay among the components and also helped maintain the density of the negative charge on the panel’s surface.

TRENDPOST: The research is what’s known as “proof of concept,” not the prototype of a device ready to be manufactured.

However, having broken through the barriers that have prevented harvesting “rain power” until now, research into a commercially practical version of the technology will speed up.

Given the world’s new normal of routine rain deluges, rain panels could have a meaningful place in the future’s energy mix.

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