food crops for energy production by making biodiesel and bioethanol
The main food crops harvested for energy are sugar-producing crops (e.g. sugarcane), starch-producing crops (e.g. corn) and oil-producing crops (e.g. rapeseed).[7] Sugarcane is a perennial crop which grows naturally after every crop without replanting, while corn and rapeseed are annual crops. Sugar- and starch-producing crops are used to make bioethanol, and oil-producing crops are used to make biodiesel. USA is the largest producer of bioethanol, while EU is the largest producer of biodiesel.[8] The energy content in the global production of bioethanol and biodiesel is 2.2 and 1.5 EJ per year, respectively.[9] Biofuel from food crops harvested for energy is also called "first-generation" or "traditional" biofuel, and has relatively low emission savings. Perennial energy crops are seen as the "[...] preferred category of crops for energy production [...]" because of high yields and "[...] a (much) better ecological profile than annual crops [...]...