If This Can be Commercially Developed ...

[Sukerkin]

http://www.bbc.co.uk/news/science-environment-14976893

... could this be the answer to our mobile energy needs? Time will tell ...

 

[cdunn]

Intriguing, but what's the primar energy source for the microbes? What do you have to feed them to make this work?

 

[Steve]

It's a Mr. Fusion! Awesome!

 

[Sukerkin]

Intriguing, but what's the primar energy source for the microbes? What do you have to feed them to make this work?

From the abstract: http://www.pnas.org/content/early/2011/09/12/1106335108



"These results show that pure H[SUB]2[/SUB] gas can efficiently be produced from virtually limitless supplies of seawater and river water, and biodegradable organic matter."

 

[cdunn]

Okay, that's insane, but neat. You can't really reasonably plug one of these into your car, but it can be a source of hydrogen to run a fuel-cell type vehicle off of, I suppose. I'm envisioning big hydrogen plants at river deltas.

 

[Sukerkin]

I think that the point is that they are self-regenerating fuel cells i.e. they replenish their own hydrogen using waste biodegradable matter to feed the microbes that serve to provide the energy to move the water through the salinity gradients to generate even more power. The power output at present is tiny, certainly not good enough be power/weight efficient but this is baby-steps territory and I am sure that things will improve as long as the avenue of research proves profitable.

 

[Dirty Dog]

An interesting idea, but there are other options...

http://pinktentacle.com/2008/05/solar-powered-bra-displays-text-holds-drinks/

What bust size, do you think, would be required to power a Prius?

And of course, you get more cupholders...

 

[Big Don]

What about adapting this to vehicles? A coil could be built into the wheel wells with magnets on the rims...

Or, put the coil in the nacelle of a jet engine and the magnets on (in) the impellers...

 

[cdunn]

What about adapting this to vehicles? A coil could be built into the wheel wells with magnets on the rims...

Or, put the coil in the nacelle of a jet engine and the magnets on (in) the impellers...

That's called a Toyota Prius.

 

[Nomad]

Apparently, there might be something to this... here's another report that reads a little better, IMO.

Five fresh/salt water exchange cells were placed in series, with the final anode being used to host bacteria. This small set of cells on its own isn’t even sufficient to produce usable current. But when directly linked to the bacterial system, it gave them a sufficient boost to liberate hydrogen, so long as they were supplied with organic matter (in their experiments, the authors used acetate). Increasing the flow of water through the cells boosted the production rate, and hydrogen continued to be released until the acetate was exhausted.

The efficiency was rather impressive. At slower flow rates, the total energy content of the hydrogen was 36 percent of the energy input into the system in the form of acetate. At this flow rate, about 85 percent of the energy stored in the hydrogen came from the salt-fresh water difference. The bacteria took the remainder of the energy from the acetate, using it for their continued survival and growth. Pumping water through the system only accounted for about one percent of the energy cost.