from Hacker News

Solar-powered desalination system requires no extra batteries

by bentocorp on 11/17/24, 10:06 PM with 45 comments

  • by terramars on 11/18/24, 2:42 PM

    This is a questionable way to present what's an excellent project and hopefully soon to be commercialized technology. The big deal here is it's a presumably installation ready application of EDR for desalination instead of RO which most systems use. This is a big deal because the membranes use electricity instead of pressure as the filter, which means everything can run at low, normal plumbing, pressures instead of the crazy high pressure RO stuff. For seawater it's borderline whether or not it will match RO for performance, but for lower salinity groundwater and industrial wastewater, it should be significantly higher performance for the same power as well as lower maintenance and capex.

    The no batteries thing is basically irrelevant to the innovation, and in fact Genius Water already offers no battery RO systems, also with questionable benefit (as well as being difficult to work with).

    I run a solar and water focused EPC in East Africa and will hopefully be working with these guys in the future when they're off the ground with a commercial system. The potential is extremely high, particularly if the maintenance overhead and operational complexity can come down in practice.

  • by elzbardico on 11/18/24, 2:39 PM

    Unlke some comments are implying, this is not a solar distiller with "additional steps". It still uses far less energy than distillation as it doesn't involve phase changes.

    It uses Electrodialysis, which is a mass separation process in which electrically charged membranes and an electrical potential difference are used to separate ionic species from an aqueous solution and other uncharged components.

  • by bastloing on 11/18/24, 1:06 PM

    That's great news! Now if they can solve the same problem with sea water, California, Arizona and Nevada can reduce their reliance on the Colorado river and grow more crops. It is only a matter of time before it's solved. Great work, MIT!

  • by computergert on 11/18/24, 4:27 PM

    I wonder what this means for the calculations outlined here: https://www.sustainabilitybynumbers.com/p/how-much-energy-do...

  • by JCharante on 11/18/24, 12:48 PM

    This seems.. simple?

  • by black_puppydog on 11/18/24, 1:50 PM

  • by cryptonector on 11/18/24, 5:48 PM

    > “The majority of the population actually lives far enough from the coast, that seawater desalination could never reach them. They consequently rely heavily on groundwater, especially in remote, low-income regions. And unfortunately, this groundwater is becoming more and more saline due to climate change,” says Jonathan Bessette, MIT PhD student in mechanical engineering. “This technology could bring sustainable, affordable clean water to underreached places around the world.”

    Uh, that's just going to increase the rate of acquifer depletion.

  • by surajrmal on 11/18/24, 1:32 PM

    Reminds me of cloud based batch jobs. We must have many more opportunistic workloads similar to this one.

  • by voidUpdate on 11/18/24, 2:22 PM

    This sounds a lot like the concept of a solar powered distiller... As in, heating a container of water with the sun, evaporating the water and then cooling it down to convert it into fresh water...