Fuel From The Fields: A Balance-Sheet What are biofuels? Made from renewable sources, biofuels promise a viable, eco-friendly substitute to fossil fuels. Can be made from a variety of crops like maize, sugarcane, beetroot, palm oil, jatropha-anything that is rich in sugar and carbohydrates. Typically, blended with petrol or diesel. Why are they controversial? Countries like the US are diverting their corn and maize crops to produce biofuels, thus contributing to the tight foodgrain position and spiralling global prices. What are the types of biofuel?