Check out Thunderf00t's videos cricising solar water collectors, e.g.:
- https://www.youtube.com/watch?v=vc7WqVMCABg - Zero Mass Water: BUSTED! "Honestly, it drives me crazy how many people have reinvented the dehumidifier, put a solar panel on it, and the media has danced around like theyve just saved the world!"
- https://www.youtube.com/watch?v=aPvXnmBIO7o - Self-filling water bottle: BUSTED! "The fact that its thermodynamically impossible seem to stop 'science communicators' from promoting this. The fact that its a really dumb, and not particularly inventive idea didnt stop the 'science communicators' from promoting this. Kinda depressing really."
Problems include:
- it's much cheaper to bring in a tanker of water from somewhere else, than for the electricity to do this.
- It's a dehumidifier; in places where the air is wet, it rains, and you don't need it. In places where you need it, you need it because there's not much water, so it doesn't work well.
- It's going to be prone to growing bacteria; warm and moist.
- It needs a vast volume of air; when water becomes steam it expands 1000x. Which means to go the other way you need at least 1000 litres of steam dragged through for a litre of water. Air can be around 4% water says Britannica.com, so 20,000 litres of humid air for a litre of water if it's perfectly efficient. Thunderf00t's estimate is 50,000 litres of air for 1 litre of water; And the air needs to be cooled. That needs big fans and lots of power (air is heavy to move).
- https://www.youtube.com/watch?v=vc7WqVMCABg - Zero Mass Water: BUSTED! "Honestly, it drives me crazy how many people have reinvented the dehumidifier, put a solar panel on it, and the media has danced around like theyve just saved the world!"
- https://www.youtube.com/watch?v=aPvXnmBIO7o - Self-filling water bottle: BUSTED! "The fact that its thermodynamically impossible seem to stop 'science communicators' from promoting this. The fact that its a really dumb, and not particularly inventive idea didnt stop the 'science communicators' from promoting this. Kinda depressing really."
Problems include:
- it's much cheaper to bring in a tanker of water from somewhere else, than for the electricity to do this.
- It's a dehumidifier; in places where the air is wet, it rains, and you don't need it. In places where you need it, you need it because there's not much water, so it doesn't work well.
- It's going to be prone to growing bacteria; warm and moist.
- It needs a vast volume of air; when water becomes steam it expands 1000x. Which means to go the other way you need at least 1000 litres of steam dragged through for a litre of water. Air can be around 4% water says Britannica.com, so 20,000 litres of humid air for a litre of water if it's perfectly efficient. Thunderf00t's estimate is 50,000 litres of air for 1 litre of water; And the air needs to be cooled. That needs big fans and lots of power (air is heavy to move).