The site in Fukuoka is only the second power plant of its type in the world, harnessing the power of osmosis to run a desalination plant in the city
The site in Fukuoka is only the second power plant of its type in the world, harnessing the power of osmosis to run a desalination plant in the city
I did not quite get how it’s a good idea tbh. They need freshwater to dilute the saltwater/brine. And they use it to separate the brine from saltwater to make freshwater? That’s definitely an energy negative cycle. So what’s the benefit? Is this more energy efficient then cleaning waste water into freshwater?
It’s easier to understand with a picture of the process:
It’s not energy negative. Osmosis doesn’t require any energy input. You only need to pump water to the plant,but the harvested power from the pressurized water exceeds the required pumping power. Freshwater and saltwater are freely available. Using the concentrated brine from a desalination plant only increases the efficiency.
I mean the part in the picture is clear to me. But if we assume freshwater is freely available, why would they want to power a desalination plant with the generated power? Basically you can trade freshwater (or salinity gradient generally) for power or power for freshwater. But in a simple loop you’d only lose both over time due to inefficiency.
From the article:
I understood it as using water not suited for household use (+ sea water) to power a plant that can create fresh water for the community?
There would be an option run desalination on solar, and osmosis generator is a base load source. So I would imagine that energy storage made out of waste product could be a potential good investment.
Right now those are pilot programmes that discover viability of those new technologies.
Even if solar/nuclear is better it’s good thing to investigate those things as in right circumstances even ski gondola can be good public transport system (La Paz)
Definitely not shitting on the tech, it’s a really cool concept and definitely useful. I just wish news outlets would have asked how the cycle is beneficial. I don’t doubt that it is, but I don’t get it.
I don’t know, so I can only guess.
The desalination plant could have been there already, because for whatever reason it was more practical (or even required) than taking the water from the river.
Or maybe the desalination plant requires very little power, maybe less than what the osmotic plant produces.
Or the whole thing is indeed energy negative, but not as energy negative as having just the desalination plant. So at least they get to use the brine from the desalination to recoup some of the energy. Because the osmotic plant is power positive.
Something stinks here and it’s not the treated sewage.
I think the idea is that if you have an unlimited supply of treated waste water, and a limited supply of fresh water and an unlimited supply of pumps and osmotic membrane and turbines you can harvest energy from the process you already need?
IDK… calling it a power plant seems like the stretch. But I’m not a languager.
doesn’t completely answer your question, but:
so it would seem it happens to be a net positive due to the energy “stored” in the brine
Hm from reading more on it, I think it has more to do with droughts in the area. That is why they build the desalination plant in the first place. I assume using the residual energy of the saline gradient (+ the boost from the brine) to generate new freshwater is better than further draining the naturally occuring freshwater. But still just a guess.