According to scientists, this technology could help generate energy at night and even underground.

In China, an innovative hydroelectric element has been developed that can generate electricity from a small amount of water and without any sunlight. This technology is reported by the website Interesting Engineering.

Researchers are working on environmentally friendly energy sources that do not rely on fossil fuels and do not produce harmful carbon emissions. One promising direction is hydrovoltaics.

Hydroelectric elements generate electricity by absorbing energy from the interaction between water and other surfaces. Like their photovoltaic counterparts, these cells typically require sunlight, and their efficiency is limited by environmental conditions such as cloud cover and wind strength.

Usually, hydroelectric elements require a continuous supply of water and low-humidity environments for optimal performance. However, scientists from the Chinese Academy of Sciences found a solution: they sealed the element airtight, making it an almost closed system, independent of external conditions. These new cells can operate in very harsh weather conditions and even at night when solar panel generators are useless.

The airtight hydroelectric element (HWE) contains an energy generation block made from technical carbon and cigarette paper. A small heterogeneous absorbing double layer, designed for the cell, creates continuous water circulation using capillary flow from the cigarette paper and slight fluctuations in ambient temperature, which cause evaporation.

The generator converts surrounding heat into output power. According to the researchers, their block generated stable electricity for 160 hours with minimal water consumption, making it ideal for deployment in areas with water scarcity, such as deserts or even underground engineering facilities.

The researchers also discovered that intense light can improve energy output. This is likely related to increased absorption of carbon soot, which increases the humidity gradient inside the cell through the photothermal effect.

Scientists believe this new technology allows for easy and inexpensive electricity generation. Since ambient heat is an inexhaustible energy source, the team has successfully converted this low-grade energy into useful power.