As the world is trying to move away from fossil fuels more research is being done on other sources of power generation. Osmotic power generation is one of new latest technologies on the block and Japan has launched its first osmotic power plant, making it the second Osmotic power plant in existence worldwide. This was the first time I heard about Osmotic power so did a bit of research on it as it sounded shady, turns out that it is actually a thing and under experimentation world wide. The Japanese plant is expected to generate about 880,000 kilowatt hours of electricity each year which is the equivalent of powering about 220 Japanese households.
Osmotic energy is a lesser-known form of energy generation that captures the energy generated from the natural salinity gradient between freshwater and saltwater.
This type of energy – also known as “blue energy” – is generated through the natural phenomenon of osmosis. This occurs when water moves from an area of lower solute concentration (freshwater) to an area of higher solute concentration (saltwater) across a semipermeable membrane. When freshwater and seawater meet, a natural gradient in salinity is created, prompting ions to migrate from the saltier side to the less salty side in pursuit of equilibrium. The movement of water and ions generates a pressure differential that can be harnessed to produce electricity. The process resembles a “silent lightning strike” occurring continuously at the confluence of rivers and oceans.
The concept has been around since the early 1970’s but due to the inefficiency of the membranes required, implementation was considered impractical but advances in membrane and pump technology are reducing these problems. That said this technology is still not as scalable as other renewable technologies (as of now) so I doubt that we will start seeing Osmotic power plants being setup all over the place that soon. One option would be to put these plants up near water desalination plants so that the waste water from those plants can be used to generate electricity more efficiently in the Osmotic power plant (With the increased salinity of water used, the plant is more efficient.
It’s nice to read about all these efforts to reduce our dependency of fossil fuels.
Source: The Guardian: Japan has opened its first osmotic power plant – so what is it and how does it work?
– Suramya