The energy gain from biofuels is often expressed as a ratio of biofuel energy output to fossil energy input. However, when considering which biofuels are the most efficient using this metric, allowance must also be made for whether or not co-products such as animal feed and other forms of energy or biomass production are involved. Economically, the value of co-products is also critical; and together with various subsidies and tax incentives associated with ethanol and biodiesel, should also be part of an economic feasibility study of biofuels production. The various uses of biomass (food and materials) are also a key factor; and local traditions and practices need to be taken into account.
From collection: Biofuels Vital Graphics - Powering Green Economy
Nieves Lopez Izquierdo