Can you extract over 500 gallons of water from the air a day for a few cents per bottle?
Well, first, the "500 gallons" part is an irrelevant distraction. If there's a machine that can extract 1 gallon a day, then 500 of them would be able to extract 500. What about the "few cents" part? That falls into the "technically true" category. However, there are a variety of other implied claims that are false.
Is this how much it will cost in practice? The 2 cents/liter figure is the "best case" scenario. Not only will most places have less humidity than is needed for that level of production/extraction, but the places with high enough humidity, where we would see the "best case" production, already have rain.
Is it revolutionary? A quick search on Amazon gets a dehumidifier that can produce up to 4 gallons a day at 170 to 260W. Taking the upper end, that's 24*260 = 6.240 kWh, or 1.560 kWh/gallon. The Skywater system, on the other hand, lists its efficiency at 2kW/h per gallon. If we take this as 2kWh/gallon, that's 78% of the efficiency of the first humidifier I found on Amazon.
Is this cost efficient? The website says that this is cheap and reduces carbon emissions, but that depends on what you're comparing it to. Certainly, fancy imported water at $2/liter is going to be more expensive than this, and probably have a higher carbon footprint, but compared to tap water, it's ridiculously expensive. 2 cents per liter sounds cheap, but that's $20/m^3. According to moneycrashers, tap water costs $2 for 1000 gallons. That's $0.53/m^3. Now, you can say "What about places that don't have tap water?", but most places that don't have tap water also don't have electricity, at least not at $0.10/kWh. And let's look at the other alternatives. According to The Guardian, it costs $18/m^3 to ship water, and desalination costs $1/m^3. Now of course shipping costs vary, and perhaps there are remote areas where it will cost significantly more, but again, where are those areas going to get electricity? As far as places where this would be useful (apart from, again, comparing it to bottled water), we are left with reasonably humid areas that don't have rain or saltwater, and are too remote to ship water. I'm not saying these places don't exist, but they certainly aren't common.
Besides the kW/h flub, there are several other red flags
Alkaline-ionized water is fundamentally different from
conventional water because the size and the shape of the
water molecule cluster has been reduced in size and
changed to a hexagonal shape,which allows the water
cluster to pass through our tissue more easily.
They claim that this water hydrates "six times more" and "washes acidic waste and other toxins from your body". They also claim that it eliminates the need for carrying heavy water bottles and needs no plumbing ... so how does the water get to you? Is the machine indoors? Do you have to get the water from the machine?