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A team of researchers were able to generate electricity using only water and metals, opening the door to a future of batteries charged solely by relative humidity.

The next source of renewable energy? Atmospheric humidity. Following the study conducted at the National University of Singapore, new research highlights the energy potential of water in the air.

Using thunderstorms as a starting point, scientists at Israel’s Tel Aviv University were able to create a device for generating electricity from relative humidity. To be precise, they produced a tiny low-voltage battery that only uses drops to recharge.

We are trying to take advantage of a natural phenomenon: electricity from water. Electricity in thunderstorms is generated only by water in its different phases: vapor, liquid droplets and ice.

Colin Price, Director of the Investigation.

The research is based on the latest work on the subject, but the basic idea owes its origin to the 19th century. In fact, in 1843, the famous English physicist Michael Faraday discovered that water droplets can charge metal surfaces due to the friction between them.

A much more recent study has shown that some metals spontaneously generate an electrical charge when exposed to relative humidity.

We explored this phenomenon, building on previous experimental knowledge and conducting new experiments to identify parameters that could improve this load.

Scientific reports.

In detail, Price and his colleagues conducted a lab experiment to determine the voltage between two different metals, exposed to high relative humidity, while one of them is grounded.

We have tried to reproduce electricity in the laboratory and found that various insulated metal surfaces are able to accumulate different amounts of water vapor charge in the atmosphere, but only if the relative humidity is above 60% . This happens almost every day in the summer in Israel and in most tropical countries.

Colin Price.

According to the scientist, the study shows that potential of humidity as a source of renewable energy.

So far we have found that the most suitable metal is zinc. By using two metal surfaces – zinc and stainless steel – we were able to achieve a maximum of 1 Volt.

Colin Price.

For comparison, an AA battery has a voltage of 1.5 V, which makes practical application possible in the future: develop batteries that can be charged with water vapor in the air.

The results can be particularly important as a source of renewable energy in developing countries, where many communities still do not have access to electricity, but the humidity is consistently at 60%.

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