4 ms·
"The current state-of-the-art in RO desalination works very well, but the cost of RO desalination driven by electricity is prohibitive," Why is taking salt out
by sayusyz 7y ago
"The current state-of-the-art in RO desalination works very well, but the cost of RO desalination driven by electricity is prohibitive,"
Why is taking salt out of sea water such a challenge?
- MuffinFlavored 7y agoIs it maybe easier to capture the rain that falls from the sky instead? The rain that falls from the sky is salt-free, right? It then becomes salty when it touches the ocean?
- phpnode 7y agoYes indeed, much easier. The problem is that the places where you need desalination tend to be the places without much rain.
- JacobDotVI 7y agoHere in the Virgin Islands, much of our personal water consumption comes via rainfall we capture from our roofs into our cisterns (big underground swimming pools). Even with that I still need to truck in water a few times a year when the rain hasn’t been sufficient. My roof surface area to consumption ratio is such that this system works pretty well for me (big roof, small human). However with a farm the roof surface area to consumption ratio is flipped - big fields needing water and little to no roof (maybe a tool shed or garage). And you can’t increase roof surface area since that would block sun from the plants. Industrial uses also have a poor ratio. Dense usage of water in a limited size building.
- justinator 7y agoThere's actually water rights/legal issues to this. For example until recently it was illegal for me to do this in Colorado; the law has changed to allow ~114 gallons/year.
- Retric 7y agoDesalination is cheap in day to day terms, it’s the scale of water we use that’s the issue. Sure, we can get ~1,000 gallons of drinking water for 3$ via desalination. That works out to a monthly water bill increase of ~45$ for a family of 5. Unfortunately, crops need incredible amounts of water. So, growing corn etc with desalination would case food prices to ~quadruple.
- riffraff 7y agoIs drip-based watering used at scale?
- BubRoss 7y agoAt what scale?
- riffraff 7y agoLarge commercial monocultures, rather than personal vegetable gardens
- JosephHatfield 7y agoDrip irrigation is heavily relied on by commercial farms in Israel
- mythrwy 7y agoIt is. t-tape for instance is widely used commercially for irrigation of high value horticultural crops like strawberries, tomatoes, peppers etc. also drip systems (with individual emitters, not t-tape) are used commercially in many tree crops (citrus etc). https://rivulis.com/product/drip-tapes-drip-lines/t-tape-drip-tape/ https://rivulis.com/product/drip-tapes-drip-lines/t-tape-dri... However for agronomic crops (like corn, wheat, soybeans, alfalfa etc), which occur in mass plantings I'm not aware of any drip applications. Certainly at minimum if drip is used for these crops, it is extremely rare and probably not practical.
- 7y ago
- comicjk 7y agoSeparating mixed things always means putting in work because it reduces entropy. Around 3% of US energy goes just to distilling oil, for instance.