Philip Winestone wrote:
Many energy expenditures occur, even/especially with oil-based
fuels. Imagine how much energy it takes to transport fuel from the
the wells to the refineries dotted about North America to the fuel
depots and then to the individual retail outlets.
Oil energy overhead is 15% to 20% depending upon where the oil
originates, and how much it needs to be processed. Most of the
overhead is at the refinery. See Appendix C, here:
http://lenr-canr.org/acrobat/NRELenergyover.pdf
Ethanol energy overhead is 60% according to the industry and well
over 100% according to others. Enzyme conversion has the potential to
increase output considerably, and it will probably bring the overhead
below 100%, but the total mass of biomass is so limited this can
never be a substantial source of energy.
- Jed