Osmotic energy coming of age?

What is osmotic energy and how could it generate one-fifth of the world’s energy needs?
https://www.weforum.org/stories/2025/09/what-is-osmotic-energy-and-how-could-it-generate-one-fifth-of-the-world-s-energy-needs/
Osmotic energy, created by the difference in salinity between river water and seawater, is emerging as a promising source of renewable electricity. Unlike wind or solar, this form of power is steady, carbon-free and naturally available wherever rivers meet the sea…

The result was a new type of nanoporous membrane: INOD (Ionic Nano Osmotic Diffusion) membrane, made from natural materials found everywhere on Earth and widely used in other industries. Combined with proprietary electrode systems, these membranes combine high ion selectivity and high ion transport, allowing more energy to be produced…

The objective is to produce electricity 24 hours a day and reach a cost of €100 per megawatt hour by 2030, competitive with main baseload sources such as nuclear, coal and gas (except gas in the United States) and cheaper than other renewable energy sources coupled with batteries…

Japan’s first osmotic power plant began operations on 5 August in Fukuoka, a southwestern prefecture. The Fukuoka District Waterworks Agency expects the power generation plant to produce 880,000 kilowatt-hours of electricity annually. The power will be used in a desalination facility that provides fresh water to the city and neighbouring areas.

DB2

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I am highly skeptical osmotic pressure could generate 1/5 of the world’s energy needs. Yes, there is an osmotic pressure differential between salt water and fresh water. It is a real thing. But it doesn’t produce a huge amount of energy.

From the link…

At a 100% capacity factor, 880,000 kwh/yr is about 100 kw constant. Only a tenth of a megawatt. (Today’s large power plants are 1000 megawatts or bigger.) They might be able to scale it up somewhat, but I don’t see it being a huge generator. The osmotic pressure differential just isn’t that much. (At least that is my understanding. Not my area of expertise.)

_ Pete

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