Treehugger picks up an article about deriving ethanol from microbial digestion as a means to energy independence. They remark on some recent commercial ventures, including:

Iogen opened a small, $40 million factory in 2004 to show it can produce cellulosic ethanol in commercial quantities. In the last two years, it has produced 65,000 gallons of ethanol that is blended with 85 percent gasoline to fuel about three dozen company and Canadian government vehicles. Oil giant Royal Dutch Shell has invested $40 million for a 30 percent ownership stake in Iogen; Petro-Canada and the Canadian government are also investors. The company will build a $350 million, commercial-scale factory next year if it can secure financing — which has long been a big if and remains one of the biggest stumbling blocks to bringing cellulosic ethanol to gas pumps. Under a best-case scenario, Passmore said Iogen won't be producing commercial quantities until 2009.

While I think this is awesome, I (apparently like many investors) am not quite so charmed by ethanol's promise just yet. There are contrarian reports as to its real energy costs, and when researchers do side with ethanol, it's often because of reduced greenhouse emissions and petrol consumption. Both of these things are good, but only incrementally.

Ethanol would be more sustainable than, say, gasoline, and this would increase our energy independence... but — if it takes a large amount of energy to make, then purify, then distribute — then where's the payoff? (I can just hear the second law of thermodynamics laughing at us now...)

Guess there's not much of a consensus just quite yet, at least among those who study energy. Which is probably why investors haven't jumped on-board yet. But with increased commercial activity comes innovation, so we'll just have to wait and see...