6

This company is marketing a product which uses the photosynthesis of a single houseplant to charge a phone.

http://www.bioo.tech/

IIRC the theoretical maximum efficiency of photosynthesis is about 10%, so at best the plant would be able to act as a solar panel with 10% efficiency. I would think, however, that much of the energy used by the plant is for growing. I do not see how they are accessing energy from the plant without (for example) burning it.

  • 1
    So, we are supposed to know about a product that is not yet released? – GEdgar Apr 25 '16 at 17:25
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    @GEdgar Yes, for example if it violates known laws of physics, then we would expect the underlying physics discovery to be making more headlines than the release of the particular gadget. For instance, I have seen claims that a certain ceramic plate will allow you to comfortably heat your room with a single candle. However (short of nuclear reactions) you can compute that the candle could only raise the temperature of the room a tenth of a degree or something. This is an example of a product which can be debunked without even looking at it. – Steven Gubkin Apr 25 '16 at 17:27
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    "However, the output of 3.5 volts and 500 milliamps is actually a little less than many USB ports." From the referenced Yahoo article on their site. – called2voyage Apr 25 '16 at 17:32
  • Is this the same product as in this question skeptics.stackexchange.com/questions/30561/…? – Reinstate Monica iamnotmaynard Apr 25 '16 at 17:41
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    I know: use the light from my iPhone's screen to shine on the plant to re-charge the iPhone... – GEdgar Apr 26 '16 at 0:43
11

Not impossible, but highly unlikely

The technology described does exist. Scientifically this is called Plant Microbial Fuel Cell. However Bioo's claims of 40 W/m² seem greatly exaggerated.

People involved in e-Plant, a Dutch company which already has similar product on the market have published a number of scientific papers in Biotechnology for Biofuels journal. Most relevant one is "The flat-plate plant-microbial fuel cell: The effect of a new design on internal resistances", which talks about improvements in efficiency, which are still nowhere near 40 W/m².

With the flat-plate design current and power density per geometric planting area were increased (from 0.15 A/m2 to 1.6 A/m2 and from 0.22 W/m2 to and 0.44 W/m2)as were current and power output per volume (from 7.5 A/m3 to 122 A/m3 and from 1.3 W/m3 to 5.8 W/m3)

As for question if they plant in pot would be able to charge cell phone, for example iPhone 6+ has 11.1Wh battery, charging losses on Li-Po batteries can be neglected.

Giving a Bioo very generous benefit of doubt, and assuming that they did something revolutionary to bring that to do 20 W/m3, such a flower pot might generate 100-200mW. Which would take 120-60 hours to charge iPhone. So it's not really feasible even with generous assumptions in their favor.

  • Thanks. I will leave the question open until tomorrow to hopefully generate some more activity, but this seems quite convincing. – Steven Gubkin Apr 25 '16 at 19:09

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