BCO can be made from a variety of feedstocks, including leaves, wood, switchgrass and algae. As it is made from waste products and algae, it will not impact the cost of food, and it will not run out.
A closer look at algae as a feedstock:
Some strains of micro algae can be used to make BCO. These make a type of oil that has energy density close to that of regular crude oil. These micro algae need very little to grow: water (which is reused each cycle) and some nutrients, primarily glucose which is very inexpensive. The algae strains also double their mass in a matter of days. That means that if half a tank is harvested for fuel, the algae will be renewed very rapidly.