[GlibMonkeyDeath]

Not surprising at all - photovoltaics yield about 50 W/m2 on average at mid-ish latitudes. Last time I checked (see below) biofuels are around 100x less efficient per acre (and in the case of algae-based biofuel, have a lot of post-processing that make them even less attractive.)

1 acre of corn ~ 500 gallons of ethanol (~6kWh/Liter for ethanol) so 50046e3 = 12 MWh/4046 m^2 ~ 3000 Wh/m^2 for corn. If there is one growing season per year, then that energy is spread over 24*365 hours. So about 0.3 W/m2 on average.

Of course, the ethanol can be stored, and has a pretty awesome energy density. So it isn't completely stupid (e.g. aircraft are a thing), although it is pretty stupid.