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Solar-Powered Toilet Torches Waste For Public Health

Daniel_Stuckey writes "With funding from the Bill and Melinda Gates Foundation's Reinvent the Toilet challenge, [a] team has developed a toilet that uses concentrated solar power to scorch and disinfect human waste, turning feces into a useful byproduct called biochar ... a sanitary charcoal material that is good for soils and agriculture. By converting solid waste to biochar (liquid waste is diverted elsewhere, as it's easier to deal with), the toilet thus allows for sanitary waste disposal without huge infrastructure investments. The toilet itself, called the Sol-Char, is a fascinating bit of engineering. In order to sanitize waste without the help of massive treatment facilities, Linden's team instead designed the toilet to scorch waste in a chamber heated by fiber optic cables that pipe in heat from solar collectors on the toilet's roof. 'A solar concentrator has all this light focused in on one centimeter. It'd be fine if we could bring everyone's fecal waste up to that one point, like burning it with a magnifying glass,' Linden said. 'But that's not practical, so we were thinking of other ways to concentrate that light.'"

11 of 126 comments (clear)

  1. Ferguson by LookIntoTheFuture · · Score: 4, Funny

    We need to think of sanitation as a business opportunity, and turn the toilet into a status symbol.

    AL (LOOKS UPWARD) Oh, dad. Look. I'm sitting on a Ferguson of my own. Just like you knew I would.

    PEGGY (BEAT) Remember this at the trial, kids.

    --
    Brave Sir Robin ran away. ("No!") Bravely ran away away. ("I didn't!")
  2. Re:So, how does it smell? by Anonymous Coward · · Score: 5, Informative

    For places without sewage plumbing but still not isolated enough that a hole in the ground is sufficient and where separation+infiltration is not viable either, there are mulching toilets, but in those you still need to change not too pleasant buckets once in a while. But there are also incinerating toilets using either gas (propane) or electricity, and they're quite OK. All that is left is a small can of ash, that can be used in the garden. This solar toilet looks to be just another way of providing the heat in such a toilet.

  3. Re:So, how does it smell? by Anonymous Coward · · Score: 3, Informative

    Eh no.
    Look up pyrolysis. Instead of simmering for hours in tropical heat, the poo will be subject to pyrolysis in mere minutes in a low oxygen environment. Gases produced will be mainly syngas, which is odourless.

  4. Re: So, how does it smell? by shitzu · · Score: 4, Interesting

    Also - it is crazy complicated. I have a "bio" outhouse in my summer house that is in essence just a plastic container. You fill the bottom and a filtering compartment with sawdust. Liquids go through sawdust and seep under a bush. Every time you take a dump you throw a bit of sawdust on it. It does not smell (actually, as i use juniper sawdust, it smells quite pleasantly like gin). The end result i put under another bush in autumn and use as a fertilizer next spring. Why would i use a complex system of solar power and fiber and lord knows how many dollars to achieve the same end result?

  5. Re: So, how does it smell? by sumdumass · · Score: 4, Insightful

    Why would you used a complex system like this? Because you are not at your summer house and instead in Haiti right after the earth quake where they can bring a bunch of these things in easily and have a more sanitary situation then waiting a year for it to decompose properly. Now exchange Haiti with any other city and any other disaster and you won't have to worry about your kids picking berries and foraging for food from the bush your neighbor shits under.

  6. Re:Bill Gates - changing people's lifes for the be by anubi · · Score: 4, Insightful

    Agreed.

    When some people accumulate enough wealth, they become empowered enough to make a difference in the history of man. Some ( like Gates ) are using their resources in a way which will benefit humanity, others will go out and buy all the rental property they can.

    I am hoping so badly ( hoping, mind you, not really anticipating ) that our lawmakers in Congress will see and craft tax law to encourage the kind of stuff Gates is doing and closing all of these tax advantages of simply rent-seeking and financial churning.

    If Gates gets favorable tax treatments for doing this kind of stuff, it only empowers him to do more similar things as well as lead others to use the power of their wealth in a similar manner.

    If there is one thing Gates has demonstrated over and over, he does have the leadership, organizational, and business skills to do it.

    I know I have left lots of anti-Microsoft rants here: I feel hypocritical in posting this. Those rants were my venting my frustration as an older guy about software becoming so un-necessarily complex with all these special interest groups trying to get their proprietary add-ons adopted into Windows that pranksters have started having a heyday leaving a mess in everyone's machine. I was rooting for a very simple but thoroughly understood OS that was pretty damned bulletproof. My feeling was if pranksters thought setting people's fancy little outhouses on fire, then what I wanted was a simple one made out of cinder block.

    --
    "Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]

  7. who writes these headlines? by cascadingstylesheet · · Score: 3, Funny

    I was thinking, "why yes, 'solar powered toilet torches', whatever those might be, probably are a waste for public health ..."

  8. Good luck getting a permit to use it by nctritech · · Score: 4, Interesting

    All the eco-friendly stuff is ignored by building codes, so while this toilet might exist and have potential, good luck getting it to pass local codes for permitting. Whether you want to build a membrane structure (like a yurt) or use composting toilets or harvest rainwater or use solar for your electricity, you'll have a hard time getting any of it approved. If they're going to make toilets like this, they need to make an effort to get building codes across the country fixed to allow lower-footprint solutions. In many places it's even illegal to live with solar/wind alone and they will come after you if you're not connected to the power grid.

  9. Re:Bill Gates - changing people's lifes for the be by Jmc23 · · Score: 4, Interesting

    yeah, because moving away from user built composting toilets with natural materials that can be maintained by a person with 1 hour of training and moving towards complex systems that depend on the latest technology, labs to manufacture and engineers to maintain is good?

    --
    Don't complain about syntax, grammar, or spelling. There is no.hell like input on android.
  10. Re:Bill Gates - changing people's lifes for the be by Will.Woodhull · · Score: 3, Informative

    In all fairness, though, traditional composting toilets can't handle the volume produced in urban settings. They may be great for homes, but not so much for apartment housing, dormitories, airport terminals, etc. Biochar toilets can be adapted to meet at least some of these needs.

    Another point: biochar acts something like a catalyst to improve soil but is not consumed in the process. The carbon is effectively sequestered for thousands of years, but biocharred enriched soils are better at appropriate release of moisture and nutrients while also diluting many soil toxins.

    This might seem like the magic cure-all to all post-modern ills, but it isn't all blue sky hype. Each gram of biochar adds the surface area of a tennis court to the soil; a little bit of it goes a long way.

    One last point: composting toilets only work well if they are properly managed. I had the misfortune of having a country neighbor for several years who was learning how to manage her composting toilet, and there were definitely episodes of odor problems.

    --
    Will
  11. Re:So, how does it smell? by Will.Woodhull · · Score: 3, Informative

    Well, yes, but with this difference: incineration pumps all the carbon in the poop into the atmosphere. Biochar production uses the heat to run a pyrolytic, anaerobic reaction where a good portion of the carbon is turned to charcoal and sequestered away for several thousand years. Since the charcoal retains the microscopic physical structures of cell walls, etc, it also has some very good soil building qualities, such as retaining fertilizers for slow release and increasing the moisture holding capability of the soil.

    --
    Will