Conventional bioethanol produced from starch (e.g. maize or wheat) and sugar crops (e.g. sugar cane and sugar beets) is the largest contributor of total biofuel production and hence the largest renewable contribution to transport. In 2012, bioethanol production exceeded biodiesel production by a factor of three, with 80 billion litres of bioethanol produced globally.
Produced from food or feed crops high in sugar or starch, conventional bioethanol production costs are dominated by feedstock costs. In 2012, conventional ethanol produced from corn in the United States was estimated to have cost between USD 0.9 and USD 1.1 per litre of gasoline equivalent (lge) to produce, while Brazilian sugar cane ethanol was estimated to have cost between USD 0.7/lge and USD 0.9/lge. The cost of ethanol from other grains (e.g. wheat) was higher. This compares to average refinery wholesale prices in the United States, with monthly averages between USD 0.72/litre and USD 0.84/litre in 2012 for gasoline.
Characterised by more complex processes, advanced bioethanol from lignocellulosic feedstocks have higher estimated costs than conventional bioethanol technologies. Advanced bioethanol is estimated to cost between USD 1.04 to USD 1.45/lge today. However, as investments in R&D increase and commercial-scale advanced bioethanol projects gain experience, advanced bioethanol technologies could see production costs fall to USD 0.7/lge for a feedstock cost of USD 30/dry tonne and USD 1.0/lge for feedstock costs of USD 100/tonne by 2020.