I wanted to work out a simple proof of concept and cost analysis for how to actually extract a meaningful amount of moisture from the air. This estimate includes the best prices I could find for each component of a reliable system which will continue to work for a period of ten years without maintenance or upgrades. It is sized for one-person. If you need to make enough water for more people, it would be more expensive and technically complex.
Let’s start with the actual moisture removal process and then talk about powering it…
Ok so this is a $43 dehumidifier which extracts 400ml per day of water from the air. This is the best price I could find.
An average person needs about a gallon of water per day minimum to survive. A gallon is 3784ml which means one person needs ten of these running nonstop to provide a constant supply of enough water for them to survive. The total cost of ten of them comes out to $430 for the dehumidifiers.
Now let’s power our moisture farm…
This dehumidifier needs 5 amps of power at 12 volts. This comes out to 60 watts per hour. That’s 1,440 watts per day per dehumidifier. Since we will need ten of them, that’s 14,400 watts per day total. This is a lot of power.
Dividing that by the rule of thumb for five hours of average 100% sunlight per day, you get a solar panel size needed of 2,880 watts. 29 100 watt solar panels will provide that. At $82/each, that comes out to a total cost of $2,378 for the panels.
Now you need an inverter to charge the batteries from the solar panels. Victron seels a very reputable one which works perfectly for this set of specifications. It costs $1,285.
The last thing we need is the batteries. We will need to store enough power each day from the solar panels to run the humidifiers until the next day. Realistically, we would need more than that because sometimes it will be cloudy so this is a very conservative estimate.
This is a very reputable standard current generation battery which gets thousands of charge cycles so it will last many years. It is rated at 12v and 100ah or 1,200 watts. Dividing our 14,400 daily needs by 1,200 we see that we will need 12 of these batteries. At $949/ea, that comes out to a total price of $11,388 for the batteries.
Parts List & Total Cost
TOTAL COST JUST $15,481!
(Price per person)