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Japan has opened its first osmotic power plant
- skybrian 1y agoIt sounds like this recovers some of the energy that the desalination plant used to create fresh water and brine from ocean water?
- nisegami 1y agoAs well as diluting the brine produced by desalination. Unclear if it's worthwhile though. As another commenter pointed out, you could treat the source of your low salinity water to produce fresh water instead and bypass a lot of this.
- ncruces 1y agoPeople are willing to waste energy to avoid drinking their own (treated) sewage, before it's temporarily mixed in the ocean.
- thfuran 1y agoIs there a more ironic way to power a desalination plant?
- Erikun 1y agoIt has a pleasant symmetry to it, I think.
- zahlman 1y agoCoverage readable (although most images are missing) without JavaScript: https://www.independent.co.uk/climate-change/news/japan-osmotic-power-plant-b2813966.html https://www.independent.co.uk/climate-change/news/japan-osmo...
- valorzard 1y agoJapan seems to really be into osmotic pressure for whatever reason. It reminds me how in Splatoon, the reason given for why the character die when they touch water is osmotic pressure and there's a whole scientific explanation about it.[1] However, that all got cut out in the international localization for some reason. Maybe there's a cultural reason why Japan is more aware this is a thing that exists? Dunno [1] https://youtu.be/N3bn57twbHM?si=nmxVjFPaeaxlTqyk https://youtu.be/N3bn57twbHM?si=nmxVjFPaeaxlTqyk
- astrange 1y agoThey like reading random Wikipedia articles I think. It's normal in kids' stories for a character to do a cool technique and then a third character to explain how the cool technique worked based on the Wikipedia article the author just read.
- numpad0 1y agoIt's routinely featured in Japanese equivalent of SAT tests. So anyone with a high school diploma at least have heard about it, most with a degree from a Japanese university have made attempts to solve a quiz involving it, and anyone with any degree from any of national universities have solved a question on that topic at least once.
- p1mrx 1y ago> it is expected to generate about 880,000 kilowatt hours of electricity each year 100 kW, in sensible units.
- speleding 1y agoPff, there has been a 50 kW osmotic plant operating in The Netherlands since 2014, how is this news? source: https://en.wikipedia.org/wiki/Osmotic_power https://en.wikipedia.org/wiki/Osmotic_power
- throwawaysoxjje 1y ago*An average of 100kW assuming 100% duty cycle.
- hinkley 1y agoExpecting it to operate most of the time is a safer bet than expecting it to have a peak output that’s substantially higher than the average. It’s be smart to try to align it with power usage, but in truth it’ll lag behind peak water usage by however long it takes to top off the tanks. I don’t know when that is but I would suspect before morning rush hour. Probably this thing peaks at 120-150KW which isn’t going to fix the grid.
- tempestn 1y agoIt's going to partially offset the power usage (and the effluent brine) of the desalination plant that feeds it.
- thfuran 1y agoA few percent of it, probably. 150 kw is peanuts for grid power generation and desalination is fairly power hungry.
- Scoundreller 1y agoI’ll take the 150 kw if you won’t
- Johnny555 1y agoDoes it generate enough electricity from freshwater to offset the energy used to desalinate more water? Would it be more efficient to just treat the freshwater that would have been used to run the plant for drinking water and desalinate less water?
- jjk166 1y agoNo, the fresh water always produces less energy than it took to desalinate the fresh water to begin with. If the freshwater is recoverable, that will always be energetically better. But if you can't recover the fresh water for some reason, like say there is a particular contaminant that is impractical to remove, or it's going to be used for some application like irrigation or feeding a nature preserve where higher salinity is tolerable but you're never getting the water back, then it reduces the overall system losses. On the other hand, there are often restrictions on how concentrated your brine can be when released so it doesn't cause environmental problems. If you have to dilute your brine anyways, might as well get a little energy back.
- aidenn0 1y agoIt seems like it would have to be more efficient to further treat the semi-treated wastewater. However there is often resistance to putting treated waste-water into reservoirs.
- throwway120385 1y agoIf you're using water at the end of a process that's just going to get mixed anyway, you're just extracting waste energy from the mixing process. Basically the fresh, used water and the highly saline water are in a lower-entropy state, and normally we'd just dump both in the ocean and allow the entropy to increase without extracting energy. But in this case we allow their entropy to increase in a controlled environment and so we're able to extract some energy in that process.
- elil17 1y agoThey really fail to explain a key point here. The reason you colocate this with a desalination plant is because you use the super-salty wastewater from desalination as the salty side of the osmosis power plant. Then you find some wastewater which is low in salt (such as semi-treated sewage), and use that as the fresh side of the osmosis power plant. The end result is that the salty wastewater is partially diluted, which means it has a lower environmental impact when it is discharged to the ocean.
- snthpy 1y agoOk so if I'm understanding your comment correctly, this "power plant" is actually reclaiming some of the energy from the desalination process?
- kulahan 1y agoWow, missing this point in the article is pretty silly - thanks for pointing that out, that’s a pretty cool aspect. But, if it’s in any way efficient, why not just use some of the fresh water you produce? Doesn’t that kinda become free power in a sense? Using fresh water to power a desalinization plant just seems counterintuitive to me, I guess, but maybe (certainly) I’m misunderstanding something
- throwmeaway222 1y agoexplains your username, explain like im like 17 thanks
- hinkley 1y agoBasically this is like the recouperator on early heat engines, but with a liquid gradient instead of a thermal one. It's making desalination more efficient and the effluent a bit easier on the ecosystem.
- HPsquared 1y agoGoes nicely with the "pressure exchanger" which recovers the pressure of the high pressure brine waste stream. Lots of heat exchanger analogies! https://en.m.wikipedia.org/wiki/Pressure_exchanger https://en.m.wikipedia.org/wiki/Pressure_exchanger
- krunck 1y agoSo let me get this straight: 1. I take a shower and produce non-salty waste water 2. That waste water and brine from a desalinization plant can be used in this plant. 3. The result is concentrated waste water and less salty brine and some power 4. The power can be used to (partially) power the desalinization plant produces fresh water from sea water and brine. 5. I get fresh water for my shower. And the diluted brine from step 3 goes to the sea? Or can it be run through the desalinization plant again? Does concentrating the waste water in step 3 also help with the eventual treatment of it
- simonbw 1y agoThe article mentions "partially treated wastewater", which I take to mean "water that we're ok with dumping into the ocean, but not ok with drinking". I think you can generally read this as a way of gaining some utility out of this partially-treated wastewater before you dump it into the ocean by mixing it with the extra-salty brine from the desalinization plant. The utility you get is: - a bit of energy that would have just been wasted - a more environmentally friendly product to dump in the ocean than just straight brine I imagine someone out there does a cost-benefit analysis to compare this system to just fully treating and reusing the wastewater and thus needing to desalinate less saltwater.
- jfengel 1y agoThe diluted brine goes out to sea. It's less harmful than dumping the concentrated brine you had before, with the bonus that you got some power out of it. The concentrated waste probably gets disposed of rather than trying to get the remaining water. You treat it like the results of a waste treatment plant. You might dehydrate it a bit, just so you don't have to ship the water, but you probably won't try to recover any more water than you already have.
- setgree 1y ago> While it is still an emerging technology being used only on a modest scale as yet, it does have an advantage over some other renewable energies in that it is available around the clock. I notice the 'some' here, and the absence of the word 'nuclear' from the article, which of course is also available around the clock. Most readers will know something about Japan's troubled relationship with nuclear power and can fill in that context themselves, but to my eyes, it's a startling omission.
- Arnavion 1y agoSome other *renewable* energies. Nuclear isn't generally considered renewable.
- wafflemaker 1y agoBut it's inexhaustible. Sun will die at some point and moon will fall down to earth. Then we'll have no solar and no waves.
- immibis 1y agoNuclear is quite exhaustible. If we use it to power everything, we have about 100 years worth. It's just another kind of fossil fuel, storing energy that was captured long ago.
- jrflowers 1y agoI love that you can post whatever you want on the internet. “Nuclear is quite exhaustible”, “The earth is flat”, “Ernest Borgnine killed JFK” you can just put words together and put them online. Such a thrill
- ranger_danger 1y ago"As a rule, strong feelings about issues do not emerge from deep understanding."
- rapsacnz 1y agoWait... so they have made a plant run by the power of mixing fresh and salt water so it can separate the salt out again?
- nickserv 1y agoExactly. Well not exactly. The desalinization plant produces brine (very salty water) as a waste product. Rather than disposing of it directly, they use the brine to generate electricity. This electricity is then used partly to run the desalinization plant. As an imperfect car analogy, the way a turbocharger uses energy from the exhaust to inject energy into the intake, in the form of compressed air. Neither is a perpetual motion engine, but both make the useful work more energy efficient.
- bill38 1y agoThis french startup has a pilot osmotic plant near Marseille : https://www.sweetch.energy/ https://www.sweetch.energy/
- yyyk 1y agoIt must be very wasteful in water - nearly all low-salinity water is easy to recycle, but here is wasted for a tiny powerplant.
- puchatek 1y agoIt uses high salinity brine that's a byproduct of desalination.
- tempestn 1y agoYour parent is talking about the "fresh" (treated wastewater) side.
- OneDeuxTriSeiGo 1y agoFukouka isn't particularly in short supply of access to water, it's just not convenient for them. The region is humid and rainy for over half the year and it's only particularly dry for about a quarter of the year. And they have a comprehensive system for evacuating stormwater during the rainy season as well. So I'd reason a guess that they have a waste water excess 1/2 to 3/4 of the year but still need the baseload capacity of the desalination plant for the remaining chunk of the year. And while you could probably switch over to plain seawater for the portion where you are running negative, it may not be worth the added maintenance/cleanup cost of having to deal with salt or brackish water for only a small portion of the year. So instead you just eat the losses for that window in exchange for the increased efficiency/lower complexity/lower operating costs.
- ggm 1y agoThis energy is not free. Solar cells and wind embody the cost of production of the device as the input cost along with cost of construction, and transmission, but the primary energy input is predicated on a real externality: Wind and Sun. This system depends on using a LOT of energy to maintain an osmotic pressure gradient. That it turn depends on pumping water across a boundary. Energy has to be expended. Now, if you run a de-salination plant and/or waste water treatment you have to expend MOST of this cost anyway, so you are scavenging energy back from an unavoidable, non-externality cost. This is a big difference. Wind and Solar bring energy in from the Sun and weather, outside human expenditure. This brings BACK some expended energy, doing another job. I suppose hypothetically, given immensely saline water CLOSE to less saline water you could expend significantly less energy to arrive at the boundary condition but its for kilowatts, not gigawatts or even megawatts. The places which have these conditions might also have high sunlight or wind conditions no?
- ch4s3 1y agoI think it's meant to help reduce the salinity of waste from the desalination plant in a process that recovers some energy to make the whole system a bit more efficient.
- deepsun 1y agoTL;DR: They made desalination 5% more efficient. It's achieved by extracting some energy from the dilution process of waste salty brine with freshwater before dumping it to a river.
- Incipient 1y ago220 households, at say $2k/year of power bills is just under $500k/year revenue, plus whatever else from "disposing" of hypersaline water (if that's even a reverse stream?) I hope this is just meant to be a tech demo, and doesn't have any advantages of scaling yet.
- bjornsing 1y agoIn 1998 when I was in high school I dreamt up this kind of power plant and asked my physics teacher where the power really came from. Not happy with his answer I asked a university physics Q&A service [1]. Not happy with their answer either I did a masters in engineering physics and kept asking this question whenever I got the chance. Never got a really good answer. But I’m glad to see it works. 1. https://fragelada.fysik.org/index.php?amne=Energi&stage=&keyword=&searchText=&page=4 https://fragelada.fysik.org/index.php?amne=Energi&stage=&key...
- bjackman 1y agoMy instinct here is just to wave it away saying "I bet the temperature of the system falls when you do this, and you need a minimum temperature for it to work over a given salinity gradient". Is it not that simple?
- schneehertz 1y agoThe freshwater used in this osmotic power plant is produced by a wastewater treatment plant, and the high-salinity water used is the wastewater generated by a seawater desalination plant So, if the freshwater produced by wastewater treatment plants is further processed into usable freshwater to replace the freshwater produced by seawater desalination plants, soon one water treatment plant could replace both the seawater desalination plant and the osmotic power plant, reducing steps. I believe this would greatly improve efficiency
- killingtime74 1y agoI believe Singapore does that and gets almost pure water. https://en.m.wikipedia.org/wiki/NEWater https://en.m.wikipedia.org/wiki/NEWater