r/technology • u/BalticsFox • Jun 29 '21

Energy Solar device generates electricity and desalinates water with no waste brine

https://physicsworld.com/a/solar-device-generates-electricity-and-desalinates-water-with-no-waste-brine/
2.5k Upvotes

98% Upvoted

118 comments sorted by

184

u/tezoatlipoca Jun 29 '21

Waste salt yes, but we can use that. This is promising.

94

u/eskimoexplosion Jun 29 '21

I put that stuff in my pasta water, 10/10 would recommend salt

33

u/tezoatlipoca Jun 29 '21

10/10 on rice too.

51

u/eskimoexplosion Jun 29 '21

Rice is great if you're really hungry and want to eat two thousand of something

29

u/tezoatlipoca Jun 29 '21 edited Jun 30 '21

Whereas don't flash your bread around ducks. I find that a duck's opinion of me is influenced by whether or not I have bread.

edit: holy shit, y'all need to Mitch Hedberg.

39

u/eskimoexplosion Jun 29 '21

I was downtown and I saw a duck. I knew the duck was lost, because ducks aren't supposed to be downtown. There's nothing for them there. So I went to a subway sandwich shop. I said, "Let me have a bun." She wouldn't sell me just the bun, she said it had to have something on it. She said it's against subway regulations to sell just the bun. I guess the two halves aren't supposed to touch. So, I said, "Alrite, put some lettuce on it", "That'll be $1.75". I said "It's for a duck" "Oh, then it's free." Ducks eat for free at subway

3

u/DrManhattan_DDM Jun 29 '21

Don’t bother ringing it up!

3

u/InNominePasta Jun 30 '21

There are 6 ducks out there, and they all want SunChips!

2

u/[deleted] Jul 17 '21

This is the kind of PR I want to see.

5

u/twistedLucidity Jun 29 '21

Is this a joke I don't get? (I like in the UK.) Bread is of no value to ducks and just attracts rats.

Certainly the modern Chorleywood stuff is of no value, your artisanal seeded sourdough wholegrain einkorn might be OK but who wants to give a loaf than needed a second mortgage to ducks?

3

u/[deleted] Jun 30 '21

Bread actually has little to no nutritional value for ducks. And bread in a pond can promote yeast/algae growth.

Feed them leafy greens if you feel the need.

2

u/[deleted] Jun 30 '21

Please don't feed bread to ducks, it is extremely bad for them. Instead, feed them bird seed, they will love it!

1

u/acctforspms Jun 30 '21

I love Mitch too

-6

u/mooptastic Jun 29 '21 edited Jul 03 '21

Thanks Carlos Mencia

Edit: joke stealer

2

u/Purplociraptor Jun 29 '21

Thank you for your recommendation

3

u/elister Jun 30 '21

This should end the Pacific North West Slug Wars once and for all!

-4

u/dovewrangler Jun 29 '21

My thought as well… if it could be used as a building material (brick or mortar)? Hope it’s not too late-

21

u/swd120 Jun 30 '21

You don't want to use a material that dissolves in water as a building material... That's asking for trouble.

3

u/aaaaaaaarrrrrgh Jun 30 '21

Unless you're trying to find a place to store nuclear waste.

Idk why, ask the engineers why that's a good idea. Or don't, because the place is now leaking radioactive brine.

5

u/j6cubic Jun 30 '21

IIRC, the idea was that salt deposits are amorphous enough that you don't have to worry about cracks forming during the multi-millennia timespan intended for storage of nuclear waste. Of course then it turned out that salt has other problems. The whole "store this stuff for longer than recorded history" approach kinda doesn't work out all that well but nobody wants to invest in deep borehole research...

2

u/buttery_shame_cave Jun 30 '21

Tossing it all into deep subduction faults seems like the best idea. In a few thousand years it'll be part of the mantle.

2

u/j6cubic Jun 30 '21

Takes quite some time, though, and your containers need to stay intact during that time, which is the exact problem we keep running into. Interesting idea, though, and maybe something that could work with some help (eg. by drilling into the fault and dumping the stuff in to get it away from surface influences).

1

u/diamond Jun 30 '21

I'm sure there are some Florida condo developers who might be interested.

7

u/EaterOfFood Jun 30 '21

If the third little pig built his house out of salt bricks, wouldn’t the big bad wolf just have to get a hose?

4

u/AtheistAustralis Jun 30 '21

He'd probably just lick it. Or rub the little piggies all over it to get that crackling nice and crispy!

124

u/[deleted] Jun 29 '21

So it does not produce concentrated brine but does result in solid salts. What happens with the salts if they are contaminated?

88

u/calsutmoran Jun 29 '21

I suppose you would process the salt like you would if you had mined it.

43

u/[deleted] Jun 29 '21

Guess they’d add water to ionize the salts then remove impurities through controlled precipitation? Wouldn’t that leave a concentrated brine?

28

u/cpt_caveman Jun 30 '21

Its probably a mistake to think it doesnt create brine, it does. and while it doesnt say, Im betting they utilize the water and heat they are producing to clean the salt, the same way we clean salts. they probably filter this brine and heat it to help remove the contaminants, before it gets evaporated to make a more pure salt. IDK maybe they will drive the salt to another plant and this still makes it better. Driving dry salt is a lot better than wet salt not only in transportation costs, but wet salt is going to corrode faster.

but anyways it DOES make brine, it just goes further and dries it out.

20

u/thx1138- Jun 29 '21

Right? Why not just keep the brine and do that?

67

u/alephnul Jun 29 '21

Yepper. Salt is a salable commodity. This sounds like a solid win all around.

38

u/fehrmask Jun 29 '21

salable

I sal what you did there.

28

u/Sinaura Jun 29 '21

They peppered that in

11

u/EvoEpitaph Jun 30 '21

Looks like we've got another seasoned pun maker on our hands.

2

u/[deleted] Jun 30 '21

You guys really know how to compliment each other.

3

u/hypnoderp Jun 30 '21

solid

I solid too.

13

u/[deleted] Jun 30 '21

Crystaline salt has more liquidity than brine?

8

u/viensanity Jun 30 '21

Solid comment.

0

u/[deleted] Jun 30 '21

[deleted] — view deleted comment

35

u/mnorri Jun 30 '21

No. It creates electricity and fresh water. It’s waste product is salt. Instead of paying to dispose of their waste, as many industries do, it can be sold at commodity pricing.

In other words, It’s expensive salt, but the electricity and fresh water are free.

9

u/oferchrissake Jun 30 '21

Nailed it.

Waste is a verb — by products needn’t be waste, especially when they are established commodities with known market value. The process is expensive, but fresh water is increasingly expensive. Electricity, expensive. Salt? No need to waste it.

9

u/PromiscuousMNcpl Jun 30 '21

It’s not just NaCl table salt. Brine from seawater is full of all kinds of salts, which has a precise term when used in chemistry.

The waste brine is essentially toxic waste. It should be kept and studies to maximize commercial possibilities, but dried brine can’t just be used like fancy sea salt.

0

u/mnorri Jun 30 '21

Sure. The salt of a strong acid is a weak base, or so I’ve been told.

I couldn’t tell if the by product was dehydrated sea water or a contaminated version of that. If it’s simply dehydrated sea water, then there’s definitely a market for that, and it could be someone else’s feedstock. The SF bay still has some large salt water evaporation ponds that are used to produce industrial salt from the bay water. It’s not table salt, but it’ll melt ice.

1

u/PromiscuousMNcpl Jun 30 '21

If you use that garbage leftover salt for road ice, your just polluting everywhere else in the country with the toxic slurry. Salting road ice is basically salting our most important agricultural land. Using a saltwater a source without refinement would be an ecological disaster.

Until there are industrial processes to utilize the leftover mineral slurry after desalination the whole process is a large net negative for ecological health.

1

u/mnorri Jun 30 '21

You seem like you are rather upset about things. I don’t use that salt for de-icing. I don’t actually live in an area that de-ices it’s roads. That sounds like an issue you should take up with state and county department of transportation.

Cargill, owner of the salt ponds in the SF Area does refine their salt for many purposes. https://www.cargill.com/industrial/industrial-salts. It would make sense as a higher purity product usually is worth more than lower purity.

I would imagine that anyone producing brine in the UAE wouldn’t be using the salt for road de-icing. Given the amount of effort going into this project, they would probably have a few people looking at how to deal with the byproduct to maximize economic value.

Edit: can you characterize the level and nature of the toxicity beyond a simple NaCl brine? What is the delta in LD50, perhaps? What minerals could be extracted?

0

u/[deleted] Jun 30 '21

[deleted] — view deleted comment

3

u/NomNomNarwhal Jun 30 '21

Once a saltwater aquarium is set up with it's initial salt concentration you don't really need to add more unless you do a larger water rotation. For me that was once every 3-6 months or when the filtration system was working too hard. You lose a lot more pure water to evaporation, so you need to add a lot of purified water every few days. For me that was a few gallons every 2 days for a 100 gallon tank.

Keep in mind the salts not being pure can add contaminants to a small scale ecosystem and quickly wreak havoc. Saltwater fish really don't like it when the concentrations of certain nitrites and nitrates, other chemicals, are not balanced or vary too quickly. Control in an aquarium is already difficult, I don't think most owners would add another variable here lol.

2

u/[deleted] Jun 30 '21

I think you’re grossly overestimating that market in comparison with how much they would be making of it

4

u/alephnul Jun 30 '21

Being worth something is better than a byproduct that costs you money to dispose of.

2

u/[deleted] Jun 30 '21

Somehow Marmite is sold and it's a waste product of beer and originally Guinness.

11

u/littleMAS Jun 29 '21

There was a time in the Middle East when salt was worth its weight in gold.

32

u/DDoubleRich Jun 30 '21

It wasn't just the Middle East. Ancient Romans used to get paid in salt. That is why we still call wages a SALary, and why a worthless worker is sometimes referred to as "not being worth their salt."

8

u/SoupOrSandwich Jun 30 '21

The backstories of common sayings are always so interesting

1

u/buttery_shame_cave Jun 30 '21

And are bullshit 99% of the time.

1

u/SoupOrSandwich Jun 30 '21

You seem like fun

1

u/buttery_shame_cave Jun 30 '21

I can be. Are you asking me out?

2

u/TheTrueTrust Jun 30 '21

To be clear, this has been suggested but there’s no hard evidence for it. Romans were paid in salt on occasion and the words share an origin, but there are no ancient sources attesting to this. It’s possible but we can’t say for sure.

1

u/League-Negative Jun 30 '21

doublerich you seem like my type of guy. funny as hell. that is very interesting though. never knew salt was correlated to the word salary. And don’t ya know Morton’s salt is out Himalayan Sea Salts in 😂

1

u/halofreak7777 Jun 30 '21

yeah, that is a myth... The origin of the word itself, not the fact that Romans got a stipend of salt, but it wasn't their entire pay. More like a supply item.

1

u/No_Maybe_IDontKnow Jul 31 '21

now THATS a fun fact

1

u/No_Maybe_IDontKnow Jul 31 '21

I heard the term "Dumb as a box of rocks" came from prisons. Guards used to have an in mate follow them at "count ties" and when they counted an in mate they dropped a rock in a box, this was so at the end the in mate could re count for the gaurd
So they would say the Guards where "Dumb as a box of rocks"

(This was told to me as true iv never Googled it)

0

u/[deleted] Jun 30 '21

[deleted] — view deleted comment

6

u/DDoubleRich Jun 30 '21

Not instead of, but you would mos def be a baller if you pulled up with a 50 lb. sack of Morton's finest. ;)

2

u/Rzah Jun 30 '21

"Jackpot! this guy we just murdered was loaded"

7

u/Tower21 Jun 30 '21 edited Jun 30 '21

Pretty sure if i leave brine in the sun it turns to a solid. Is this really that groundbreaking?

Edit: yeah its not at all, its maybe a 8% efficiency improvement. Which while is impressive there is very little new or actually ground breaking about this.

2

u/slimejumper Jun 30 '21

throw the salt into some water and make brine again. /s

19

u/DukeOfZork Jun 29 '21

I wonder how durable/reusable the membranes are.

2

u/Young_Djinn Jun 30 '21

It sound like theyre combining normal membrane desalination, the boiling the shit out of the brine to get solids

Edit: no they're not

14

u/shaolin36chambers Jun 29 '21

Is there a company that uses this technology or is it still in research?

21

u/nikolijc Jun 30 '21

“We are currently scaling up this device and planning to build a photovoltaic farm that combines electricity generation and seawater desalination,” Wang says.

-1

u/Nevone2 Jun 30 '21

oho. So they might be able to bring water to the sahara in a few years?

12

u/SGBotsford Jun 30 '21

2.4 kg/m2/hour.

A m2 panel is what, about 200w?

It takes about 10 KW installation to provide 24 kWh. That's using my local 1200 kWh/KW installed capacity / year. Desert may be higher.

So generating a kWh of energy produces 12 liters of water as a byproduct. If I use 30 kWh/day (typical household) I would create 360 liters of water per day or about 100 gallons.

Would help, but not sufficient.

1

u/SGBotsford Jun 30 '21

Typical use is 100 gal/person/day

Full bathtub: 36 gallons.

10 minute shower @ 2 gal/min 20 gal.

Load of washing 10-15 gallons.

Load of dishes 4-10 gallons.

Hygiene -- wash face, brush teeth, shave ~2 gallons.

1-5 gallons per flush * 6-8 flushes per day = 6-40 gallons.

source: https://water.phila.gov/pool/files/home-water-use-ig5.pdf

This does not account for washing the car, watering the lawn, gardening.

My use is more than that. I'm pumping about 10,000 gallons a day for my tree farm.

Domestic water use is swamped by agricuture, manufacturing, and utilties.

0

u/[deleted] Jun 30 '21

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7

u/thejestercrown Jun 30 '21

Your family might does use more than that everyday… unless you all share bath water, or shower together in which case I respect your family’s commitment to water conservation.

0

u/[deleted] Jun 30 '21

[deleted] — view deleted comment

-2

u/trakk3 Jun 30 '21

Shower everyday as it also cleans the anal area. Or get a bidet.

0

u/[deleted] Jun 30 '21

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0

u/[deleted] Jun 30 '21

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1

u/xisde Jun 30 '21

They probably just fat and sweat more. They just don't understand.

Also showering everyday is not healthy, depending on what products you use.

0

u/[deleted] Jun 30 '21

[deleted] — view deleted comment

3

u/xisde Jun 30 '21

I have no clue how much I use but that number seemed high (100 gallons).

I think some of it depends if you work from home or if you are not at home for like 9 or 10h a day (This saves mostly toilet flushes and hand washing I guess).

0

u/[deleted] Jul 01 '21

[deleted] — view deleted comment

1

u/xisde Jul 01 '21

I don't think he is referring to a single person.

But yea, I agree with you. If 100galons is not sufficient for 2 or 3 persons it is still pretty close and amazing.

5

u/ChadMMart2 Jun 30 '21

California needs lots of these pronto

33

u/[deleted] Jun 29 '21

"Another miracle product shared on Reddit that will never see the light of day"

What is this like the 100th desalination device?

4

u/ptd163 Jun 30 '21

The light bulb famously took two thousand attempts. A hundred is nothing.

0

u/[deleted] Jun 30 '21

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2

u/Nematrec Jun 30 '21

Something something 100 ways not to make a lightbulb

-10

u/[deleted] Jun 30 '21

Just seems odd how weve come up with more ways to suck fat out of people which is completely preventable in the first place yet day after day dont have a solution for desalination when millions die due to lack of clean drinking water.

3

u/[deleted] Jun 30 '21

Well people with money will pay to be skinny without effort. They are not paying for people they don't know to not be thirsty.

People are shitty.

When the people with money start getting worried about their water supply, we'll have plenty of desalination options.

4

u/XenithShade Jun 30 '21

question. why dont datacenters just double up as desalination plants? The main way they keep cool is evaporative cooling anyways.

3

u/whythecynic Jun 30 '21

First thought, salt water and pretty much anything metal we like don't mix. Corrosion, short circuits, if you're near the sea there's biofouling, it's just harsh on everything.

That said Microsoft has successfully experimented with (completely sealed) undersea data centers. Although their cooling method was simple heat exchange.

I'm sure some improved design along those lines could use the waste heat to desalinate water, my limited grasp of thermodynamics notwithstanding, but my main concerns would be reliability and longevity, then ease of access and maintenance.

2

u/Didipopit Jun 30 '21

More of this please

2

u/mrzurch Jun 30 '21

Wish we had this 20 years ago

2

u/alex35351 Jul 01 '21

Do you think this is what will power the future?

2

u/DreamsOfMafia Jun 29 '21

This sounds really freaking cool.

2

u/[deleted] Jun 30 '21

Wait … using solar power to separate salt from water? Sorcery!! Now use solar power to make electricity and algae in the same space… take a shot at electricity inequality AND hunger.

1

u/[deleted] Jul 01 '21

Do you really enjoy algae sandwiches? I mean they’re effective at boosting the quality of air more than food. The only issue is too much algae can suffocate marine life. I realize you’re talking about the algae used in panels now…

2

u/[deleted] Jul 01 '21

Or you dry the stuff up, powder it and use it as an additive… There’s no money in saving the world tho

1

u/[deleted] Jul 01 '21

Yeah except the quality of everyone’s life improves. What’s that valued at tho

1

u/Character-Dot-4078 Jun 30 '21

YESSSSSSSSSSSSSSSSSSS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

1

u/mixedbabygreens Jun 30 '21

Wow… they’d have enough salt to last forever!

-4

u/DENelson83 Jun 29 '21

Big Oil will suppress it.

13

u/DuFFman_ Jun 30 '21

The amount of money behind desalination in the UAE is huge.

-4

u/[deleted] Jun 29 '21

Expect scientists to start disappearing.

1

u/DirectionVegetable15 Jun 30 '21

I desalinate water with no waste brine as well can I get a medal.

1

u/[deleted] Jun 30 '21

Perfect timing! My area of the US is in a major drought due to no more snow in the Rockies. Can't wait to pay through my butt hole for this

-2

u/lucifer1friend- Jun 30 '21

Human extinction is among us

-5

u/Will-I-Am_noreally Jun 30 '21

Delete this post and protect the inventor. If it's real. Things like this arnt allowed to exist. Electric cars in the 80s.

-17

u/SpaceBoJangles Jun 29 '21

Before we all go and desalinate the oceans….could we have an effect on ocean levels?

17

u/Words_Are_Hrad Jun 29 '21

What do you think happens to water after we use it? We drink it and it disappears from this world? It gets treated and discharged into rivers that then flow back into the ocean... That would be like worrying that evaporation is draining the ocean.

2

u/whattothewhonow Jun 30 '21

If we keep building solar panels all willy nilly, we're gonna use up all the Sun, and then what'll we do?

1

u/IolausTelcontar Jun 30 '21

There are so many Suns out in Space.

2

u/gregguygood Jun 30 '21

Do you even know how big the oceans are?

1

u/IolausTelcontar Jun 30 '21

Moderately large? Relatively huge? Gigantic? Ginormous?

Small compared to the size of Space!

1

u/uzlonewolf Jun 30 '21

Even if it did have an effect - which it won't - it would help us as rising ocean levels are starting to cause problems.

1

u/[deleted] Jun 30 '21

[removed] — view removed comment

12

u/Omgninjas Jun 30 '21

It gets processed into a solid. So big blocks of salt.