Study highlights problems linked to converting crops into biofuels. Taking up valuable land and growing edible crops for biofuels poses a dilemma: Is it ethical to produce inefficient renewable energies at the expense of an already malnourished population? Researchers highlight the problems linked to converting a variety of crops into biofuels. Not only are these renewable energies inefficient, they are also economically and environmentally costly and nowhere near as productive as projected.