Slashdot Mirror
Water From Wind
ghostcorps recommends a writeup in The Australian by columnist Phillip Adams about a new windmill design that extracts water from air. The article gives few details of how it works, because patent protection is not yet in place, but what is revealed sounds promising. "[Max] Whisson's design has many blades, each as aerodynamic as an aircraft wing, and each employing 'lift' to get the device spinning... They don't face into the wind like a conventional windmill; they're arranged vertically, within an elegant column, and take the wind from any direction... The secret of Max's design is how his windmills, whirring away in the merest hint of a wind, cool the air as it passes by... With three or four of Max's magical machines on hills at our farm we could fill the tanks and troughs, and weather the drought. One small Whisson windmill on the roof of a suburban house could keep your taps flowing. Biggies on office buildings, whoppers on skyscrapers, could give independence from the city's water supply. And plonk a few hundred in marginal outback land — specifically to water tree-lots — and you could start to improve local rainfall."
Things I would like to know:
1. Does this design perform better than other windmill designs (for generation).
2. What will this do to the atmospheric conditions?
3. If everyone has one....will it no longer rain?
Layne
Excellent, so now anyone living near, but not in a city can enjoy a barren landscape when the rain no longer falls.
Alright, sarcasm aside, surely there are bound to be some less-than-good effects on the surrounding enviroment if large amounts of water are 'sucked' out of the atmosphere prematurely?
We can now turn the Australian Outback into Tattooine. We now have vaporators!
One small Whisson windmill on the roof of a suburban house could keep your taps flowing. Biggies on office buildings, whoppers on skyscrapers, could give independence from the city's water supply.
And enough of them and the humidity of the air will drop, reducing all of these miracle machines to a trickle. Probably not good for the local plant and wildlife, too. Rain is important.
Weaselmancer
rediculous.
So, condensing water from the air to water trees, from which some of the water will transpire back to the atmosphere, might improve local rainfall? Is that like the "lose money on every sale, but we make it up in volume" line? :)
No, it's more that this windmill does what trees in a rainforest are already doing. Israel noticed this some time ago, and spent most of the 1960s and 1970s on something similar, though theirs was based on water pumped out of salinated lakes and the Medditeranian, and placed in desalination tanks. The fresh water was used for tree farms, that created more rainfall by cooling the air.
Therefore, the windmill in this situation is just a placeholder for what the trees will do anyway once they're mature enough.
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
the article states that with these windmills, water will be replenished into the air from the oceans. how do we know this? how was this proven?
and if the water content of oceans diminishes, the salt content increases proportionately. that would threaten to bring dramatic change to the fragile balance of the environment for marine life.
when man plays with mother nature, we almost inevitably come out on the losing end.
* drain the swamps in new orleans, then lose 60% of the land's ability to absorb water.
* introduce pest-killing amphibians to the everglades, then they procreate without preditors and wipe out existing species.
* water the deserts of nevada to make lush golf courses, then people in colorado go thirsty and firemen can't put out historically large forest fires covering hundreds of thousands of acres.
Remember kids, if you're not paying for the service, YOU ARE THE PRODUCT THAT IS BEING SOLD.
For some reason, the technology described just reminds me of a venturi nozzle. http://en.wikipedia.org/wiki/Venturi
Understand that moisture content in the air is established by temperature and pressure. There is water in Australia, its just not dropping out of the sky. If you extract moisture from the air, then when that air is in the presence of liquid water it will induce some evaporation. That being said, this system could work either by using the reduced pressure from the airfoil surface or more likely by actually creating some compression and then having a decompression path for the air that goes through a condenser. All that being said, I was in Australia a couple of months ago and speaking as someone from California I'd say that if they put flow restrictors on their faucets it would do them a world of good. Sure taking a shower in a 6gpm shower is luxurious but really, do you really care about conserving water if you let your water run free like that? Low flow toilets? Nope. Granted I was mostly in the cities (Sydney, Canberra, etc) but still it seemed there wasn't a lot of "internalizing" what it means to live in a drought. --C
From what I see there will be many side effects of such a system. First, as many have mentioned, it will pull moisture out of the air. This means that there will be less moisture downwind and with enough of these windmills, a dry region. That said, though, taking moisture out of the air increase the amount of room in the air for more moisture and thereby would allow evaporation downwind to be more efficient. On the other hand, if there is no rain replenishing the water, it would eventually all dry out. Second, since it has a cooling effect, this also means the air temperature would drop downwind. In fact, with enough of them, you may cause a significant drop in temperature. Not only is it dry at that point, but its also cold. Since colder air cannot hold moisture as well as warmer air, this cancels out any increased efficiency in evaporation. Third, if you drop the temperature enough, you might hit your dewpoint. You also might not considering you are removing moisture from the air and thereby lowering the dewpoint. Lets say for now you do hit your dewpoint because the removal of moisture isn't as effective as the decrease in temperature. Anyone who knows anything about weather knows if the temperature reaches the dewpoint, it start to rain. This means there is more moisture in the air than the air can hold. Now its raining removing even more of the moisture from the air, though putting it on our dry cold region we were talking about. At that point, its just a cold region though dropping water out of the air may cause a region further away to now become our dry cold region. Last, as people have also noted, there will be a low pressure area in our cold region. Storms tend to develop between high and low pressure regions under some circumstances and at the very least, high winds. If our cold region isn't a stormy cold region and that point, its a windy cold region. But then again, the air of the high pressure area will probably be warmer than our windy cold region which then makes it warmer. So now we just have a windy region. If the windmills slow down the air at all, then everything may just equal out in the end. I think it would take a meteorologist of some experience and perhaps someone of the more physical science persuasion to work out all the effects and if it will have any overall effect.
If you have enough room you can use solar distillers to purify the water. The water goes through a bend with a pinhole in the top and VOCs are removed, and everything else is left behind.
If not, you can use a particulate filter, a carbon filter, and then a reverse osmosis filter, but this requires using a pump to develop at least 40 psi, at least in models I've seen (and the one I own.) Then again, you could use another windmill to drive the pump.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
There are some ancient dew collectors. Check this one.
Man, you really need that seminar!
Deserts exist mainly because there is no moisture in the air to be extracted, not because of a lack of extraction.
Depends on the desert. Some exist where mankind imported goats, which ate all of the vegetation down to nothing. The first usually has drought-resistant plants still around, like cactus and the like, and shouldn't be messed with. The second, like what exists in Australia, Northern Africa, and the Middle East, usually has no vegetation to speak of and high humidity. These deserts can be rehabilitated with planting and air moisture extraction (though this is the first large scale version I've seen- earlier ones I've been aware of use desalinated sea water pumped many miles to kick off the vegetation first). The second type is usually very rocky and sandy as well, the soil having been eroded away by the wind once the vegetation was gone. For this reason, many environmentalists in those areas consider goats to be weapons of mass destruction.
SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.