A new solar desalination system takes in saltwater and heats it with natural sunlight. The system flushes out accumulated salt, so replacement parts aren’t needed often, meaning the system could potentially produce drinking water that is cheaper than tap water.
"The researchers estimate that if the system is scaled up to the size of a small suitcase, it could produce about 4 to 6 liters of drinking water per hour and last several years before requiring replacement parts. At this scale and performance, the system could produce drinking water at a rate and price that is cheaper than tap water."
Holy eff, I was expecting "per day" after 4-6 liters from a suitcase size device... That's more water than I consume in a day, even on double flush days. Of course it would only be during daylight, and with full sun I imagine. But that's still so much water!
While this is a cool development I would recommend tempering expectations. The cost of tap water is exceptionally cheap and the claims made here likely take these estimates to the extremes. The economics of scale likely don't match up.
For example, tap water in my city costs ~$0.04 per gallon, at 5 liters per hour, 0.264 gallons per liter, 24 hours per day, for 5 years is $2,312. So saying they can make it for less than the cost of tap water doesn't mean it's affordable.
For example, tap water in my city costs ~$0.04 per gallon, at 5 gallons per hour, 24 hours per day, for 5 years is $1,752. So saying they can make it for less than the cost of tap water doesn’t mean it’s affordable.
Or maybe the product just isn't for you, but for people who pay significantly more for, or possibly don't have access to drinkable tap water at all.
Your tap water is expensive! Is that a typical rate? Its $551 for me for the 5l/hr for 5 years. $0.0075 per gallon.
This is in UK. Its billed at £1.98/1000l.
I have family that can't drink their tap water because it's practically brackish (is was entirely brackish when someone pierced the aquifer boundary and created a hole that filled the underground reservoir with the nearby sea water, that lasted about 18 months, the entire community was on water that was being trucked in while a new well was discovered and drilled), their water is insanely subsidized, and still pretty expensive. The community is about 200 houses, each with access to Ocean/River inlet water, I don't know a single one of them that wouldn't go for this option. Their water is so heavily mineralized that filters lifetimes are hours to days. And then maybe they can allow the aquifers to refill, and maybe their houses wouldn't be sinking as quickly...
I've been on boats with RO filters that are about the same size and can produce about the same amount of fresh water. The thing is that's no where near "cheaper than tap water." Tap water production and consumption is measured in acre-feet.
A significant amount of researchers seem to author these kinds of papers that sound great but then can't be reliably reproduced, or are completely impractical in application. The NileRed video about his attempts to create the compressed wood "armor" was very illuminating to this point.
Ah yes, and I also have a bridge here in my bag to sell you!
It's sad that this is yet another thing endorsed by MIT that's yet again vaporware. MIT used to mean something, now I automatically assume it's nonsense.