A reader over at AutoblogGreen (one of my all-time favorite blogs) sent in a short essay comparing the efficiency of photovoltaics to the efficiency of biofuels. and ABG rightly saw fit to publish it.

I'm not tremendously surprised that photovoltaics won...I'm just surprised by how big the difference is.

Now biofuels are kinda like solar power. Plants capture the the sun's light and convert it to energy. We then convert the plants into fuel, and then turn the fuel into useful power.

Photovoltaics skip a few of those steps, converting sunlight directly to power without any pesky nature getting in the way. It turns out that creating biofuel with an acre of land produces about 100 times less power than covering that same land with solar panels.

While it's fascinating to discover, the sad fact is, it doesn't really matter. We can hope that someday our global footprint will shrink.  But right now, it doesn't matter how much space we take up, it only matters how much money we spend. What we really need to see is a per-unit-of-power analysis of the cost of biofuels vs. photovoltaics. It's my guess that that analysis will make it quite obvious why no one's replacing corn fields with solar panels.

Via AutoblogGreen

A potential new fuel has been developed by researchers from the University of Georgia using wood chips. Small bits of wood are heated in an oxygen-free environment to produce charcoal and a gas. The gas can then be condensed into a liquid bio-oil which can be processed into a fuel which can be blended like bio-diesel. The charcoal is being investigated for use as a fertilizer. Since much of the carbon from the wood or plant matter becomes charcoal, rather than part of the fuel, if the charcoal is put back into the ground as fertilizer, then this fuel is net carbon negative.

You're taking carbon out of the atmosphere when you grow a plant, and if you don't use all of that carbon and return some of it to the soil in an inert form, you're actually decreasing the amount of carbon dioxide in the atmosphere," Adams explained. "We're optimistic because in most types of soil, carbon char has very beneficial effects on the ecology of the soil, its productivity and its ability to maintain fertility.

One potential drawback to this is that only 15-17 percent of the dry weight of wood is turned into this fuel. The charcoal produced accounts for another 33 percent of the weight of wood. But that still leaves roughly 50 percent of the byproducts of this process unaccounted for. We aren't told if that material becomes useful materials or waste?

via: 25x25 Tips