ENERGY RETURN ON ENERGY INVESTMENT (EROEI)
FIGURE 10.51 The left panel compares the EROEI for extraction and refining of crude oil or growing, harvesting, and processing of biomass, for several fuels. The number of kilometers traveled by a vehicle using the amount of fuel produced from investment of 1 gigajoule of energy in production of the fuel is shown in the right panel. A gigajoule is approximately equivalent to the energy content of 27 liters of crude oil. (Data from Schmer et al., 2008; Inman, 2013)