Could osmotic energy replace batteries, asks Institute Polytechnique de Paris, in a far-reaching review. Osmotic energy is a source of renewable power, harvested from the salinity gradient. This gradient is the progression where fresh water from a river meets seawater in the ocean.
How Osmotic Energy Could Replace Batteries
Osmotic energy – the popular name is blue energy – first arrived on the scene in the 18th Century. Scientific interest in the principle is growing as the world searches for fossil fuel alternatives. The broad principles are as follows, according to Institute Polytechnique de Paris:
When a body of fresh water is brought into contact with salt water, and separated by a thin membrane that is permeable only to water molecules, the osmotic pressure produced as the fresh water passes into the salt water, can be harnessed to generate electricity.
The potential from this principle is huge. It could generate electricity consistently 24 hours a day, without requiring energy storage. Osmotic energy could therefore replace utility batteries, all things being equal. Although we would presumably still need batteries for portable energy.
Salinity gradients develop naturally in deltas and estuaries, where fresh river water meets ocean water. We could generate ‘blue energy’ regardless of weather conditions, because the natural flow does not depend on the wind or the sun.
Tentative Fingers Into This Immense Potential
French start-up Sweetch Energy2 launched a pilot osmotic plant in 2023, at the mouth of the Rhône river where it enters the Mediterranean Sea. As we write, this project is still in the prototype phase, although the longer term goal is to produce 500 megawatts of electricity.
This quantity compares well with the output of a single coal power station, and could meet the energy needs of 1,5 million people. The Institute Polytechnique de Paris is of the opinion this technology could eventually satisfy around 15% of global energy needs.
This certainly is a technology that could help counter the scourge of global warming. However, from what we understand, this would only be part of the solution. So could osmotic energy replace grid batteries in their entirety? It seems not, but it could certainly be a significant partner.
More Information
Storage Batteries On The Ocean Blue
Abundant Green Batteries From the Oceans
