I imagine a trillion of these floating along the coast of the western United States, little landing pads (and solar powered charging stations) for a trillion drones that can move the freshly desalinated water from the ocean to the nearest forest fire. You need a drone cloud 500 million strong to deliver 100 million gallons of fresh water to X location immediately? No problem. Need a drone cloud to water your 20,000 acre vineyard? Coming right up. Who needs clouds?
Simple, solar-powered water desalination (2020)
181–190 of 241 posts
Re: Simple, solar-powered water desalination (2020)
#182FTA: "Unlike some desalination systems, there is no accumulation of salt or concentrated brines to be disposed of. In a free-floating configuration, any salt that accumulates during the day would simply be carried back out at night through the wicking material and back into the seawater, according to the researchers." The capabilities are freaking interesting, but let's say someone builds a big enough settlement on a…
This chunk from the article is, unfortunately, an outright lie. By definition, removing salt from seawater leaves you with water and salt. The article handwaves the salt away by supposing that the desalinator will float on top of the ocean. In actual production configurations other than towing it behind your sailboat, you will end up with a brine pool that needs to be disposed of, or a concentration in the wicking ma…
Water in open ocean is not still - there are currents. I suppose if you had a large enough operation you could create a gradient of sufficient size to be self-sustaining without further mechanical agitation (such as your example of towing behind a ship). It would be an interesting exercise to see a large collection of these in operation. Heck even if you had to pump ocean water on land and back out to dilute the brine this process would still use significantly less energy overall than current desalinization plants.
Speaking of current plants, a recently constructed one in Carlsbad CA leverages the cooling outflow of a power plant to handle the dilution. The power plant was already there and so was the outflow - these things can be planned to leverage overlapping uses to further increase efficiency.
Re: Simple, solar-powered water desalination (2020)
#183Earlier quoted context omitted.
Why not release the salt back to the sea? Presumably it would not increase the salt content of the ocean very much considering the vastness of the ocean and the sheer quantity of fresh water that is being added to it by melting glaciers, etc? What am I missing?
Why not just collect the salt, and sell it as... salt? Even if its not ok for cooking, it should be fine for roads? I am sure there are other industrial uses for salt.
Salt from roads is seriously contaminating our environment and significantly impacting farming in more and more areas.
Ever hear of the Romans salting the earth of people the conquered? It was so they couldn't grow crops - yet we routinely do this to ourselves - pretty daft.
Re: Simple, solar-powered water desalination (2020)
#184California is building the largest desalination plant in the US.(2015) Is this ready yet ?? https://news.ycombinator.com/item?id=10343296
Largest SOLAR desalination plant in the US. The article doesn't seem to list the numbers but this article https://www.businessinsider.com/california-waterfx-solar-des... seems to indicate the next step up from their demo plant was a plant capable of 2M gal/day.
Hopefully they are still developing the technology, it seems like it could be a life-changer for small farming communities around the world.
By contrast the biggest 'traditional' desalination plant in the US makes 50M gal/day and the biggest plant in the world makes around 260M gal/day (US gallons).
Re: Simple, solar-powered water desalination (2020)
#185Earlier quoted context omitted.
The salt you release isn't instantly diluted in the whole ocean and we're speaking, for a plant, of millions cubic meters of salt enriched water per day. The release area is just dying.
Can you provide a source for that? I dove near a desalination plant exit pipe in Saudi, the impact on the marine live did not seem to big in the area. But it was a small plant for a few thousand people and we did not do a proper assessment. I don't doubt there is an effect, but am not convinced that the "release area just dying" is correct.
https://www.keiken-engineering.com/en/brine-disposal-how-eff...
Brine disposal is indeed a complex issue. Should be noted the above URL is from a desalinization industry proponent so I would say it's probably a little more optimistically biased but it was one of the better summaries I found so it still has value from that perspective. If you do more digging around each of the solutions they discuss you can find more pro's/con's for each and you will quickly find out that it is a pretty significant issue.
Re: Simple, solar-powered water desalination (2020)
#186I imagine a trillion of these floating along the coast of the western United States, little landing pads (and solar powered charging stations) for a trillion drones that can move the freshly desalinated water from the ocean to the nearest forest fire. You need a drone cloud 500 million strong to deliver 100 million gallons of fresh water to X location immediately? No problem. Need a drone cloud to water your 20,000 a…
Water is very heavy though. For watering crops I think you would do better in terms of energy efficiency with land-based infrastructure. At the very least, if you're going with drones, you ideally want something more energy-efficient than quadcopters.
Re: Simple, solar-powered water desalination (2020)
#187Earlier quoted context omitted.
I am pretty sure if you had to get your water from one of these devices you would not be using it to flush toilets or other non-essential use. And actually it does seem like 'drinking water' is actually drinking water and not for all those other uses you mentioned. As 3.7 litres is the amount required for a human male each day. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...
>I am pretty sure if you had to get your water from one of these devices you would not be using it to flush toilets or other non-essential use. Are you suggesting that toilets, showers, washing machines use salt water?
Is there a problem with flushing a toilet with salt water?
Re: Simple, solar-powered water desalination (2020)
#188Earlier quoted context omitted.
Is the water cycle not a thing any more?
A large part of the fresh water generated may be used for watering crops or gardens, and would thus evaporate in part. The evaporated water in desert areas would probably rain back down far way, and take long to mix with the sea near the plant again. For example, the Red Sea has much higher salinity that other oceans due to high evaporation and narrow connections to the other oceans. I doubt the effect is large thoug…
Indeed - the dead sea has stupid high salinity because the only way water leaves is via evaporation :)
It is a very odd sensation to "swim" in the dead sea. Even floating is pretty hard because you are so buoyant. It's probably the closes to true weightlessness I will ever get.
Re: Simple, solar-powered water desalination (2020)
#189I imagine a trillion of these floating along the coast of the western United States, little landing pads (and solar powered charging stations) for a trillion drones that can move the freshly desalinated water from the ocean to the nearest forest fire. You need a drone cloud 500 million strong to deliver 100 million gallons of fresh water to X location immediately? No problem. Need a drone cloud to water your 20,000 a…
A trillion? Well I guess efficiency doesn't concern you...
Re: Simple, solar-powered water desalination (2020)
#190I imagine a trillion of these floating along the coast of the western United States, little landing pads (and solar powered charging stations) for a trillion drones that can move the freshly desalinated water from the ocean to the nearest forest fire. You need a drone cloud 500 million strong to deliver 100 million gallons of fresh water to X location immediately? No problem. Need a drone cloud to water your 20,000 a…
A trillion? Well I guess efficiency doesn't concern you...
It's wild ass guess, but imagine a drone fleet capable of delivering that quantity of water on demand.
We will see this in our lifetimes. Rain on demand.