The world needs new and clean ways to make energy so we can stop climate change. One very interesting idea is called osmotic power.
A company in France, Sweetch Energy, is working hard on this technology. They are making progress that could change how we get renewable energy in the future.
Want to learn more about this new energy generation technique? Let’s talk about it.
What is Osmotic Power?
Osmotic power is a way to make electricity from the natural difference between fresh water and salt water. Think about a river flowing into the sea. The river water is fresh, with very little salt. The sea water is salty, with a lot of salt. Where these two meet, there is a natural change in how much salt is in the water.
This difference in saltiness can create energy through a process called osmosis. Imagine you have a special thin sheet, like a very fine filter, that lets water pass through but not salt. If you put fresh water on one side of this sheet and salt water on the other, the fresh water will naturally try to move to the salty side to mix and make the saltiness equal.
This movement of water creates pressure. We can capture this pressure and use it to turn a turbine, just like in a dam, which then makes electricity. It’s like a quiet, continuous power source that happens naturally where rivers meet the ocean. Scientists sometimes call this “blue energy.”
The idea of using osmotic power isn’t new. People started thinking about it in the 1970s. But for many years, it was hard to make it work well enough to be useful. The biggest problem was the special sheets, called membranes, needed to let the water through but stop the salt.
These early membranes weren’t very good at letting enough water move, so they didn’t produce much energy. Some projects tried to use osmotic power, but they didn’t work very well on a large scale.
For example, a company in the Netherlands built a small demonstration plant in 2014, but it only made a tiny bit of power. A big energy company in Norway also built a demonstration plant in 2009, but they had to stop using it in 2013 because it cost too much to run and didn’t make enough energy.
So, while the idea was good, the technology to make it work efficiently wasn’t there yet.
Sweetch Energy’s New Technology
Now, a French company called Sweetch Energy, started by two scientists, Bruno Mottet and Lydéric Bocquet, has come up with a new technology that could change everything. They have invented something called Ionic Nano Osmotic Diffusion (INOD). This new technology looks like it can finally unlock the power of osmosis on a large scale.
The secret to Sweetch Energy’s success is their special new membranes. These membranes are made from natural materials using very advanced technology to create tiny holes, only ten nanometers wide (a nanometer is incredibly small).
These tiny holes allow water to move through much more easily than the materials used in old membranes, but they still block the salt. This means they can get much more energy from the same amount of water.
Sweetch Energy’s technology could produce about 20 to 25 watts of power for every square meter of membrane. This is a huge improvement compared to the old membranes, which could only produce about 1 watt per square meter.
Also, because Sweetch Energy uses natural materials that are already available in industries to make their membranes, they believe they can reduce the cost of the materials to only one-tenth of what it costs now.
This would make osmotic power a truly energy-efficient and affordable way to get clean energy.
Building a Test Plant for the Future
Sweetch Energy isn’t just working in a lab. For more than three years, they have been taking big steps to build plants that can produce osmotic energy on an industrial scale. At the end of 2024, their first test plant, called OsmoRhone, started working.
This plant is located where the Rhône River flows into the Mediterranean Sea, which is a very salty sea. They chose this river because it has the biggest potential for making osmotic electricity in France, about one-third of all the energy made by water power on the Rhône River.
In the beginning, this test plant will only make a small amount of power, just a few dozen kilowatts. But the plan is to gradually increase the amount of power they produce in the coming years.
In the long run, OsmoRhone is expected to have a production capacity of 500 megawatts. That’s enough energy to power over 1.5 million homes, which is about the size of cities like Barcelona, Amsterdam, or Montreal!
As they build more plants and the technology gets better, the cost of osmotic power is expected to go down. This will make it more competitive with other clean energy sources like solar and wind power.
The Bright Future of Osmotic Energy
One of the best things about osmotic energy is that it can produce power all the time, no matter what the weather is like. Unlike solar power, which only works when the sun is shining, or wind power, which only works when the wind is blowing, osmotic energy relies on the steady and predictable flow of rivers into the sea. This makes it a very reliable source of energy.
If osmotic power becomes successful, it could really change how we get our energy. Unlike power plants that burn fossil fuels, it doesn’t produce carbon dioxide, which causes climate change. It’s a clean way to make energy.
Also, during the osmosis process, the water that goes back into the environment is mostly the same as it was before, with very little impact on the ecosystem. Scientists will need to study the long-term effects, especially on the saltiness of the water where it returns to the sea, but early signs are promising.
The potential for osmotic power around the world is huge. Some estimates say that osmotic energy could provide up to 15% of all the electricity the world needs if we use it properly. In places like Greenland, where glaciers are melting a lot due to climate change, the increased flow of fresh water into the sea could actually provide more water to generate osmotic power.
At the same time, using osmotic power could help fight the very climate change that is causing the glaciers to melt. This shows how this technology has the potential to solve both energy and environmental problems on a global scale.
Sources:
Leave a Reply