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Microbe Powered Wireless River Network

Pour dirt on them and let them grow
  [vote for,

Large numbers of riverine communities (e.g. in Congo or the Amazon) do not have internet access.

It would be costly to build cables and/or satellite receiver infrastructures to get these people connected, because they live spread out over vast distances, and because they are poor.

Going wireless might be an option, but keeping the transmitters online requires an off-grid, decentralised baseload energy source.

An interesting approach would be to launch hydrogen balloons with light-weight wireless transmitters [see link]. But recovering these devices in the jungle areas would obviously be impossible.

My alternative is simple: use rivers and the organic material that flows through them to build a low-cost network.

-these rivers are flat, so they offer a good line of sight at which to place the light-weight, low-power, low-cost wireless transmitters

-make a submersible microbial fuel cell to power the transmitters. Contrary to solar or wind or hydro, SMFCs work all the time, day and night, and even when water is stagnant. Bacteria convert organic matter into electricity. No batteries needed either.

-now attach the transmitters to the SMFC buoys and place them so that they signal to each other.

That's it.

django, Sep 05 2008

Wireless data via hydrogen balloons http://www.spacedata.net/
Google is interested in these guys. [django, Sep 05 2008]

Submersible Microbial Fuel Cell http://www.scienced...ef15072b739c4fd01e4
The first demonstration of a microbial fuel cell as a viable power supply: Powering a meteorological buoy [django, Sep 05 2008]

Hydrological map of Central Africa http://www.ce.utexa...ebfiles/dcwriv2.gif
Plenty of flat rivers, with lots of organic material in them [django, Sep 05 2008]

Breakthrough: 15-fold increase in power density http://www.scienced...5b36d51274e18cd3daa
Single chamber air-cathode microbial fuel cells (MFCs) that lack a proton exchange membrane (PEM) hold a great promise for many practical applications due to their low operational cost, simple configuration and relative high power density. One of the great challenges for PEM-less MFC is that the Coulombic efficiency is much lower than those containing PEM. In this study, single-chamber PEM-less MFCs were adapted by applying a J-Cloth layer on the water-facing side of air cathode. Due to the significant reduction of oxygen diffusion by the J-Cloth, the MFCs with two-layers of J-Cloth demonstrated an over 100% increase in Coulombic efficiency in comparison with those without J-Cloth (71% versus 35%) at the same current density of 0.6 mA cm². A new cell configuration, cloth electrode assembly (CEA), therefore, was designed by sandwiching the cloth between the anode and the cathode. Such an MFC configuration greatly reduced the internal resistance, resulting in a power density of 627 W m³ when operated in fed-batch mode and 1010 W m³ in continuous-flow mode, which is the highest reported power density for MFCs and more than 15 times higher than those reported for air-cathode MFCs using similar electrode materials. [django, Sep 12 2008]

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       Also suitable for your sewernet.
phoenix, Sep 05 2008

       If these are in rivers, could they not be powered by a propeller-powered generator? Less gimmicky than the microbes, which would be a hard thing for a country mechanic to fix.
bungston, Sep 05 2008

       [bungston] many of these rivers are not powerful enough for hydropower, and the waterflow also fluctuates heavily with the seasons. So you would need some kind of battery backup system.   

       Microbial fuel cells have no mechanical parts. They require virtually no maintenance, that's why they're so interesting for remote, off-grid applications [see the paper in the link.]
django, Sep 05 2008

       Might be a hard sell to environmentalists who are concerned about foreign species.   

       MFCs are cool technology to be sure, and something like a 12V DC powered router might be a good fit.
Bcrosby, Sep 05 2008

       [Bcrosby] what do you mean by foreign species?
django, Sep 06 2008

       Species without proper passport.
zeno, Sep 06 2008

       Like humans on mars... [+]
xxobot, Sep 12 2008

       The 24 milliwatts of power of the fuel cell in the link seems to be too low.   

       By the time you uprate it to produce sufficient power, alternative technologies (solar cells) might prove to be more viable.
neelandan, Sep 12 2008

       [Neelandan] solar would require batteries (there are no viable alternative energy storage media yet for solar).   

       So every so many weeks/months, you'd have to mount an entire expidition to replace the batteries.   

       The big advantage of microbial fuel cells is that they're permanently delivering power.   

       Also, I merely linked to the submersible cell to point out the feasibility of putting the cell onto a river bed. This particular cell's power output is low.   

       But major progress is being made in this technology. A recent breakthrough increased power output of MFCs 15-fold [link].
django, Sep 12 2008


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