How would you solve the water abundance XPrize?

[PraAnan]

Hi everyone,

This was the criteria for the competition:
The Water Abundance Prize tasks competing teams with developing technologies that can harvest 2,000 liters (528 gal) of water from the atmosphere each day, using only renewable energy at a cost of no more than two centers per liter (0.26 gal).

A couple of days ago the 5 finalists were picked.
https://water.xprize.org/press-release/five-teams-advance-final-round-of-175m-water-abundance-xprize

Two of the finalists (Hydro Harvest and Skydra) don't mention anything about their product, JMCC Wing seems to be more about an electricity generator that's attached to typical air to water unit, Veragon / Thinair seem to be using a new type of surface material that enhances the process of condensation and lastly Uruavu who are using what they call a solar adsorption reactor to harvest water from the air by using the power of the sun.

After reading all this I was curious to know about how the engineering experts on these forums would tackle the situation. What do you think of the finalists?

Thanks for reading.

 

[OmCheeto]

Hi everyone,

This was the criteria for the competition:
The Water Abundance Prize tasks competing teams with developing technologies that can harvest 2,000 liters (528 gal) of water from the atmosphere each day, using only renewable energy at a cost of no more than two centers per liter (0.26 gal).

A couple of days ago the 5 finalists were picked.
https://water.xprize.org/press-release/five-teams-advance-final-round-of-175m-water-abundance-xprize

Two of the finalists (Hydro Harvest and Skydra) don't mention anything about their product, JMCC Wing seems to be more about an electricity generator that's attached to typical air to water unit, Veragon / Thinair seem to be using a new type of surface material that enhances the process of condensation and lastly Uruavu who are using what they call a solar adsorption reactor to harvest water from the air by using the power of the sun.

After reading all this I was curious to know about how the engineering experts on these forums would tackle the situation. What do you think of the finalists?

Thanks for reading.

I hope you weren't expecting an answer today, as they've been working on this project for 1.4 years!

October 24, 2016 Prize Launch & Registration Opens​

ps. I'm working on it.
So far, I've come up with an average relative humidity of 65% for the 5 participating nations, and an air flow rate of 500 cubic meters per minute, assuming the device operates for 6 hours per day. Box fans and solar panels can do that for about $0.000061/liter of water. The condenser is going to be a bit tougher.

Of course, this is just back of napkin maths, so I'd multiply the cost so far by at least 3, and at the most 10.

 

[256bits]

A roof, gutters, and a rain barrel.
And collect enough to average out when its not raining.
That would do the trick.
Inexpensive, low maintenance ( usually ), hands off operation, and non-gadgety for simple folk.

 

[Baluncore]

A long hollow bladed wind turbine that draws air in at the centre through a pressure regulator. The pressure drop causes condensation of water, the wet air then flows through a rapidly spinning felt disk that mops up the liquid and throws it outwards like a centrifugal pump to an annular collector at atmospheric pressure.

 

[OCR]

A roof, gutters, and a rain barrel.

I'd have a problem with that ... .

 

[OmCheeto]

A roof, gutters, and a rain barrel.
And collect enough to average out when its not raining.
That would do the trick.
Inexpensive, low maintenance ( usually ), hands off operation, and non-gadgety for simple folk.

Did you check the maths for your house and region?
My roof is approximately 7 times too small to collect the required amount of water in my region. (44 inches/year rainfall * 1024 ft^2 roof = 291 liters/day)
Though, my property is almost the exact right size for the 2000 liters/day:
required area: 7036 ft^2
property area: 7020 ft^2

Also, it would require ten 55 gallon rain barrels to collect 2000 liters.

--------

To expand a bit on my idea:

I would have to know how much to cool the air to reach the dew point.
Wiki claims that:

T_dp ≈ T - (100 - RH)/5
T is in celsius
​

I collected data points for 32 cities yesterday: city name, relative humidity, time, date, and temperature.
hmmmm...
As I said, this may take some time to analyze...

Here are 11 of my data point collection sites:

ps. Fun project!

 

[OmCheeto]

pps.

This might kill my idea:

"a device"​

reference: The rules...

Curse you! Rules!

Pretty sure that "digging a hole in the ground" to store "coolness" negates my most awesome of ideas.

 

[PraAnan]

pps.

This might kill my idea:

"a device"​

reference: The rules...

Curse you! Rules!

Pretty sure that "digging a hole in the ground" to store "coolness" negates my most awesome of ideas.

If it's a cool and interesting idea you should totally go ahead. I mean you're not entering the competition so a bit of leeway should be ok.

 

[OmCheeto]

If it's a cool and interesting idea you should totally go ahead. I mean you're not entering the competition so a bit of leeway should be ok.

Well, right off the bat this morning, I picked probably the worst city for my device: Hyderabad, Telangana, India
Optimal dew point vs minimal seasonal temperatures are simply too close together for my idea to work there, IMHO.

I will have to look at Uravu's idea, and work from there.

and lastly Uruavu who are using what they call a solar adsorption reactor to harvest water from the air by using the power of the sun

Do you have a link for anything more specific as to how it works?

I found "Its based on startup’s patent-pending solar adsorption reactor technology. Modular and scalable, it works efficiently even in dry and arid areas." at https://www.indianweb2.com/2018/03/23/indian-startup-creating-water-from-thin-air-is-in-finals-of-los-angeles-based-xprize/, but nothing beyond that.

 

[PraAnan]

Do you have a link for anything more specific as to how it works?

No, that + the picture of their prototype is the most amount of info that I can find about their tech.

 

[OmCheeto]

No, that + the picture of their prototype is the most amount of info that I can find about their tech.

Well, I guess we just have to guess how it works then.
"Solar adsorption" sounds a bit like:

The Einstein–Szilard or Einstein refrigerator is an absorption refrigerator which has no moving parts, operates at constant pressure, and requires only a heat source to operate.​

That sounds like a great start!

And as someone who recently won an award said;

Einstein-inspired Isobar vaccine cooling system wins UK James Dyson award

“I am so pleased that this technology can get a bit of the limelight,” he added. “It was such an innovative technology in 1929 that was forgotten and taken over by electric refrigeration. It gives me the confidence to pursue it with my whole heart in the knowledge that I can actually make this device and that it could have a great impact for the benefit of thousands of people.” He paid tribute to the help of his tutor at Loughborough, Dr John McCardle, and for his “constant scrutiny” over hundreds of hours of development.​

I have very little background in refrigeration, so it would probably take me a few years to figure this out.

 

[Stephenk53]

A roof, gutters, and a rain barrel.
And collect enough to average out when its not raining.
That would do the trick.
Inexpensive, low maintenance ( usually ), hands off operation, and non-gadgety for simple folk.

Doesnt it need to be able to gather the water even when it is not raining so that it gathers it every day

 

[256bits]

Doesnt it need to be able to gather the water even when it is not raining so that it gathers it every day

The guidelines do say 2000 litres minimum per day so you probably are correct that the collection is outside the guidelines.
But does that mean everyday?
And at every geographical location on the earth?
And where there is cloud cover most times of the year?
And locations where there is no wind?
And low humidity?

One of the requirements of the contest is renewable energy. If the sun isn't shining, or the wind isn't blowing, one can not be able to collect the needed water with an idle machine.

So my proposal to collect the water falling from the sky, and store enough of it for a rainy dry days, making sure an extraction of 2000 L / day is possible for extended periods of time.
Of course that is what a vast majority of people do at the present using natures reservoir, either from the rivers, lakes, or wells, with nature doing the extraction from the atmosphere itself. For free.

that's my proposal and I'm sticking to it.
Where's my 1.5$ prize.

 

[256bits]

so I'd multiply the cost so far by at least 3, and at the most 10.

Is that operating cost with or without initial capital cost outlay of solar panels, or the birth of a wind farm?

 

[OmCheeto]

Is that operating cost with or without initial capital cost outlay of solar panels, or the birth of a wind farm?

That is all capital cost.