(Co-founder at Charm) Fair points. I'm not going to defend corn ethanol - our process yields 10x more saleable energy per acre than corn ethanol. The energy cro

(Co-founder at Charm) Fair points. I'm not going to defend corn ethanol - our process yields 10x more saleable energy per acre than corn ethanol. The energy crop we're currently field trialing is similar to sugarcane, with extremely high yields (and our process uses the entire plant, unlike ethanol). Of course, energy crops are only required at large scale. At small scale, there's plenty of agricultural waste available for cheap, as you mentioned. PV certainly wins on efficiency compared to crops, but it's also relatively expensive (an acre of PV vs an acre of perennial crops). Also PV is quite unremarkable at removing CO2 from the atmosphere :]