New method turns rainfall into clean electricity

A team has invented a new method that turns rainfall into electricity.

Finding new sources of clean energy is a priority for many companies and consumers alike. If humanity expects to continue breathing fresh air, our reliance on fossil fuels needs to decrease. Already, parts of the world experience life-threatening pollution levels on a daily basis.

It will be up to methods like solar and wind energy to start making clean electricity mainstream. However, scientists are also constantly pursuing new ways to harness energy from the world around us. A team from the City University of Hong Kong has discovered a method that generates electricity from rainfall.

Let It Pour

Rain can evoke different reactions depending on where you live. In the desert, it is a sign of life and is often celebrated as it relieves a months-long drought. In northwest America, it’s a dreary part of daily life.

Someday soon, rainfall might be just as valuable to clean energy production as sunlight. The team from Hong Kong has developed a technique that produces a jolt of electricity from rainfall.

They say that just one drop can briefly generate 140 volts. That’s enough to power 100 LED lightbulbs for a short period. The team’s droplet-based electricity generator (DEG) uses a “field-effect transistor-style structure” to transform rainfall into quick flashes of power. It is made of a material called PTFE that contains a quasi-permanent electrical charge. Each drop of rain bridges two electrodes to trigger a new flow of energy.

The team published its research in the journal Nature.

Of course, there is one drawback. Between jolts of electricity, the material needs time to recharge. This means that it isn’t quite ready for practical applications.

Nonetheless, it is a wholly unique approach to clean energy. Rather than using the kinetic force of rushing water or the heat of the sun, it can transform the relatively tiny amount of energy in one raindrop into a huge amount of power.

Forecasting the Possibilities

The DEG needs to be refined before it can be used to generate power for something other than an experiment. Nonetheless, it isn’t hard to see the potential uses for the technology.

It could be placed on a rooftop in large sheets that harness power every time it rains. Although it would be a less-constant form of clean energy collection than solar power, it may be more effective in overcast, rainy climates. Even if it can’t provide enough electricity to power a whole building, anything that could be harvested is better than nothing.

Meanwhile, the DEG might have other, less ambitious uses as well. For instance, it could be integrated into smart products that often get wet—like a connected water bottle. Interestingly enough those products not only exist but are (very slowly) becoming more popular. With sporadic water contact, a smart bottle equipped with a mini DEG could generate enough electricity to power itself.

However, this breakthrough isn’t exciting because of what it can do now. Rather, it is a sign of hope for the future. The more ways we have to generate clean energy, the better. If we can harness a meaningful amount of electricity from rainfall, that will help decrease our reliance on dirty energy even more.


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