Microbial Fuel Cells

A reader asks if microbial fuel cells fall into the category of “bad ideas” for clean energy that I mentioned in my post yesterday.  He cites: Major Advance Made in Generating Electricity from Waste Water, Teaching A Microbe To Make Fuel, and And Energy Innovation – Snails and Griddies.

Right.  Personally, I see very little reason to be excited about microbial fuel cells for any purpose other than academic interest.  We live in a world that is consuming 15 terawatts, and the fact that microbes emit electrons as a part of their metabolic processes has the potential to make very little difference in the scheme of things.

I ask you to recall the “energy pyramid” that we all learned in grade school science, where our biosphere powers itself with photosynthesizing organisms that capture the energy from the sun.  Obviously, these organisms evolve for the purpose of surviving and reproducing, not for storing lots of extra energy so human beings could come along a few billion years later and run their air conditioners.   Can microbes be tapped for a small amount of electric energy? Yes. Will that ever represent a cost-effective and scalable energy solution? No. Not in another billion years.

Keep in mind Michio Kaku‘s concept of the Class One, Class Two, and Class Three civilizations.  A Class One civilization (to which we aspire) gets its energy from its local star.  In our case, we receive 6000 times more energy from our sun every day that all seven billion of us are using.  We need the lowest cost, most efficient way of pulling that off, which means figuring out the most direct and immediate way of transferring the energy in those photons to create electrical potential.  At this point, that looks mainly like solar and wind.