Thunderf00t
6 HN mentions · mentioned in 6 months, 2018–2025
18:01 · 1.1M views · May 25, 2018
Thunderf00t argues that Zero Mass Water's solar-powered atmospheric water generator is essentially a dehumidifier with solar panels. He critiques its economics and physics, especially in arid places.
Cited in threads on atmospheric water harvesting as the standard debunking of such startups.
6 comments from Hacker News
Check out Thunderf00t's videos cricising solar water collectors, e.g.: - this video - 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!" - [LINK] - 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).
Like the startups which try to make solar systems to condense drinking water from the air. They demonstrate it in wet climates where the idea works but the solar panels don't because it's cloudy and cool. Those environments don't need drinking water because they are rainy. Then they try it in deserts where the water is needed and the solar panel bit works, but the whole thing doesn't work because there's no water in the air - that's why the water is needed there(!). ThunderF00t Busted! videos on scammy startups keeping on raising money for this fundamentally unworkable idea: - this video - Zero Mass Water - [LINK] - Fontus self-filling water bottle - [LINK] - self-filling water bottle lab experiment what would be reasonably possible - [LINK] - WaterSeer part 1 - [LINK] - WaterSeer part 2 Drinking game: drink every time he says "it's a. de. humidifier."
Wow, I was under the impression that atmospheric water harvesting (AWH) was extremely inefficient. I don't have any numbers but things like [1][2] seem to indicate that AWH is currently not very useful. The paper doesn't seem to (if I read it correctly) actually address this directly, instead it talks about how much energy is needed to extract water at different relative humidity levels and factors in the potential energy generated through solar panels. It also looks at the usefulness of this process given factors such as existing access to clean water (or lack thereof) and population. I didn't looking beyond the 'Methods' section, I hope I didn't miss anything here. [1]: [LINK] and/or [LINK] (talk about same silly product) [2]: this video
Zero Mass Water: A startup selling specialized panels that use solar power and batteries to pull water from the air. The goal is to reduce the amount of energy needed to access clean drinking water without geographical limitations. There is a lot of energy involved in the phase change of water. We've also had dehumidifiers for over 100 years. The takeaway from that is, dehumidifiers produce don't produce water well in arid environments. this video This makes me wonder if the Gates Foundation is properly utilizing scientific expertise.
Zero Mass Water -BUSTED! this video You can do your own research for the other solutions presented in the article. I find the idea of groundwater recharge interesting. We dump large amounts of water into the sea having used the Earth as a Atmospheric Water Harvester. We need to be keeping all that.