It's a myth that biofuels consumes more fossil fuels than it produces. In fact a study found biodiesel produced from soybean produces 93% more energy than it consumes while corn ethanol produces 25% more energy than it consumes.
http://www.pnas.org/cgi/content/full/103/30/11206
The question is not whenever biofuels are energy efficient, but how economicaly viable are they. Remember the oil sands weren't economically viable 50 years ago, but technology slowly changed that.