EROI — A Tool To Predict The Best Energy Mix
Energy Returned on Investment, or EROI, is the ratio of energy returned to energy invested in that energy source, along its entire life-cycle. When the number is large, energy from that source is easy to get and cheap. However, when the number is small, the energy from that source is difficult to get and expensive. The break-even number for fueling modern society is about 7. The working EROI for each energy source is - Nuclear 75, Hydro 35, Coal 30, Closed-Cycle Gas Turbine 28, Solar Thermal 9, Wind 4, Biomass 4, and Solar PV 2. A future mix without nuclear cannot sustain modern society without a lot of fossil fuel.