The Impact of Biofuels

One of the entrepreneurs whose project is included on our list of the clean energy business investment opportunities just sent me this article from Time Magazine on biofuels.  The author’s point, in brief, is that we tend to underestimate the damage that most biofuels do to the environment; he is completely correct, IMO.

There are several mechanisms at work here, but they largely come down to land use.  In some areas, farmers are planting crops whose ultimate use is biofuel, opting to go in this direction rather than planting food crops.  In other areas, large swaths of ecologically beneficial forests are being removed to make room to grow the biomass that will be processed into fuels. 

At the core of the problem is the miniscule efficiency by which the sun’s energy is converted to a usable fuel.  None of these plant species evolved to store lots of extra chemical energy so we could come along and put it in our gas tanks.

If there is hope here, it lies in algae, which is 30 – 50 times more energy-dense than any terrestrial plant.  Having said that, it appears that we’re a very long way from the ability to scale up the growth of algae to the point that it makes a significant contribution here.

I believe that, by the time (if any) that algae becomes feasible, the need for liquid hydrocarbon fuels will have disappeared, and electric transportation will have emerged dominant.  Because of the relatively low efficiency of internal combustion engines and the relatively high efficiency of charging and discharging batteries, we would replace every drop of gasoline and diesel in the U.S. by raising the output of our electrical generation capacity by less than 14%.  That’s not nothing, but it’s achievable, and I believe that’s where we’re headed.