Scientists demonstrate that electricity may be obtainable from water with a high salt concentration

As the world comes to terms with the realities of climate change and the limits of the Earth's natural resources, it's important to develop renewable sources of energy. Scientists from the Institute of Scientific and Industrial Research at Osaka University have shown that electricity can be obtained from water with a high salt concentration.

Some people think of Osmosis as just a science term that they had to learn in school. When there is a concentration difference between the two sides, electricity can be generated. The salty water in the oceans may be used to help alleviate the demand for energy. In order for this to be practical, it needs to be very thin and highlyselective.

A research team led by Osaka University has used conventional Semiconductor processing technology to control the structure and arrangement ofnanopores in an ultrathin Silicon The fabrication methods have been around for a long time. It is possible to control the size and location of the pores.

"Wherever there is a non-equilibrium situation, such as two water tanks with different salt concentrations, there is often an opportunity to covert this energy into electricity," says first author Tsutsui.

The device was able to reach a peak power efficiency of 400 kilowatts/m 2. The researchers found that the power that could be obtained was reduced by adding too manypores to the membranes. The osmotic power density of 100 W/m 2 was achieved by the optimal configuration of the 100 nanometer-sizednanopores.

It was important to understand how to design the best power generation device. "Many other research groups are promising 'green' energy, but we go one step further and propose 'blue' energy based on ocean water that can be applied on an industrial scale," senior author Tomoji Kawai said. Future projects might include ways to scale up the devices for real world testing after the study was published.

More information: Makusu Tsutsui et al, Sparse multi-nanopore osmotic power generators, Cell Reports Physical Science (2022). DOI: 10.1016/j.xcrp.2022.101065 Journal information: Cell Reports Physical Science