https://www.powershow.com/download/3b604b-ZGQwN/Pressure_Exc...
Read the history, including how the then-current prototype (out of series of improved versions developed over the 12 years it took to get to a market ready design) and all the inventor's personal belongings were lost in the invasion of Kuwait.
>One particularly efficient type of pressure exchanger is a rotary pressure exchanger. This device uses a cylindrical rotor with longitudinal ducts parallel to its rotational axis. The rotor spins inside a sleeve between two end covers. Pressure energy is transferred directly from the high pressure stream to the low pressure stream in the ducts of the rotor. Some fluid that remains in the ducts serves as a barrier that inhibits mixing between the streams. This rotational action is similar to that of an old fashioned machine gun firing high pressure bullets and it is continuously refilled with new fluid cartridges. The ducts of the rotor charge and discharge as the pressure transfer process repeats itself.
A long time ago, as a kid i read about a experiment in a GEO-magazine harvesting water directly from air. The used idea was a hygroscopic chemical (Silicagel) collects the moisture from the air. Sunlight heats the silica gel- which releases the moisture as steam- which then condenses in a destil. It was very little water for a lot of effort, but the complete lack of moving parts and self-containedness of such a system deeply impressed me, being young and with Frank Herberts Dune on my mind.
To drop such a contraption into the deep dessert, where it could keep a plant alive, become a oasis with no basis ..
Its hard describing this fascination with self-contained or only slowly expanding pockets of life.. imagine a glass bubble , filled with small plants, beatles and life, thriving in the midst of a frozzen over wasteland like mars or a dessert like the death valley.
Its like a https://en.wikipedia.org/wiki/Bottle_garden but without the surrounding walls..
https://www.youtube.com/watch?v=XPSYzLZ7xKU
https://www.sciencemag.org/news/2019/09/crystalline-nets-har...
From the panel to the outlet, you only get out from 10 to 15% of input solar power, while thermal desal can use nearly all of it right away, and it leaves more concentrated brine. Multiple effect desal will probably move the efficiency up a bit. It's nowhere near clear cut.
Also if you have low potential reject heat from power plants, it's idea for desal use.
If you have nuclear as your heat source, then economy-wise thermal desal will beat electric many times over.
I recently read about thermochemical, and electrochmical desalination methods which can be added atop a thermal plant, further increasing thermal desalination efficiency.
I can't imagine why you'd use batteries at all. Storing fresh water efficiently is cheap, storing power efficiently is not.
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I’ve heard on the grapevine that facilities are now being designed which work at under 100% capacity in order to soak up excess/cheap power.
I believe this is coming about because: 1) the high cost of power and presence of sporadically cheap power makes it economically viable, and 2) designing equipment with lower duty cycles can actually provide substantial cost savings. Ie a facility which only runs 50% of the time is much cheaper to build & run than once which runs 100% of the time.
Sorry I cannot cite sources right now.
Imagine doing shift planning at such a site though. Eight days from now, there's a 60% chance of wind in excess of 5m/s between 22.00 and 06.00. But labour costs would be 130% higher than 06.00 to 14.00 on that day. On that morning shift there's a 50% chance of clear skies ...
This means that you just staff it at a consistent level and plan the work around the energy levels.
You either have losses in:
* Underutilized solar generation
* Underutilized plant capacity
* Overhead of energy storage
Design your system to minimize that cost. Engineering systems of all sorts are full of this kind of optimization problem: "Should I add a subsystem to recover loss x?" There is always more you can do to recover losses, but each extra system you add suffers diminishing returns a little more.
It does mean much larger service water tanks as you need to buffer demand but if you have lots of "free" solar power then it may well be worth it.
This system gets approximately 6 liters/hour/sq m... so it makes sense if we can manufacturer it for less than 40 dollars per square meter and space is cheap.
Not for a large desalination project. You will pay close to the spot price. Which is 30-45 cents.
Your biggest cost will be labor anyway. And the osmosis membrane, which needs to be regularly replaced, unlike the panels.
I have had these feelings since I saw the Egypt map showing how much of it is just not usable.
I wonder if RO based desalination has any learning rate associated with it and whether a lot of CAPEX costs are related to some proprietary IP. I know that a lot of OPEX is energy costs and hopeful that solar will get even more cheaper with time and even more scale. However if the same can be done with scaling of RO technologies and reducing costs to say ~20 % of existing a great many opportunities will arise.
Really hope it will be lower than 0.1 $ / m3 before 2030.
For large scale desalination, you need to attach tiny magnetic particles (think nano-scale) to the salt, and then extract it with magnets. And as a byproduct, you'll get Lithium.