‘Jumping’ Water Droplets Could Produce Electricity

In the quest for better forms of renewable energy, researchers have looked at all manner of potential sources: the sun, the wind, the ocean, even volcanoes.

Researchers at MIT have stumbled across another potential source of energy: condensation in the air.

While investigating how water droplets interact with superhydrophobic (water repellant) surfaces, the team discovered that the repelled droplets produce a net positive electrical charge as they jump away from the surface.

According to the MIT release about the project:

“The initial finding that droplets could jump from a condenser surface — a component at the heart of most of the world’s electricity-generating power plants — provided a mechanism for enhancing the efficiency of heat transfer on those condensers, and thus improving power plants’ overall efficiency. The new finding now provides a way of enhancing that efficiency even more: By applying the appropriate charge to a nearby metal plate, jumping droplets can be pulled away from the surface, reducing the likelihood of their being pushed back onto the condenser either by gravity or by the drag created by the flow of the surrounding vapor toward the surface.”

The findings also suggest that power could be generated via condensation in the ambient air. By placing two water repellant metal plates outside, energy could theoretically be produced by the water droplets jumping from one plate to another.

You can read the findings in Nature Communications. The MIT press release can be found here.

Lead researcher Nenad Miljkovic of the school’s NanoEngineering Group, says the team will build a prototype to test the idea next year. You can read about some of the group’s other superhydrophobic surface research here.

Source: Quartz