… is from page 193 of Michael Shellenberger’s excellent 2020 book, Apocalypse Never: Why Environmental Alarmism Hurts Us All (footnotes deleted):
The main problem with biofuels – the land required – stems from their low power density. If the United States were to replace all of its gasoline with corn ethanol, it would need an area 50 percent larger than all of the current U.S. cropland.
Even the most efficient biofuels, like those made from soybeans, require 450 to 750 times more land than [does] petroleum. The best performing biofuel, sugarcane ethanol, widely used in Brazil, requires 400 times more land to produce the same amount of energy as petroleum.