What contribution do each of the fuels (slide 31) make? [Alan]
Pounds of CO2 per million BTU energy generated (https://www.eia.gov/environment/emissions/co2_vol_mass.php)
Jet Fuel 156.3
Natural Gas 117.00
A critical question not answered here is the efficiency of the vehicle. Thus diesel engines may emit less CO2 per mile travelled than gasoline vehicles if the engine is more efficient (higher mpg) – but see above
Electricity is not a fuel comparable to the others. Conventional electricity is generated in a power plant (utility) where some fuel source is needed to power a turbine. The question is what powers the turbine? This can be any of the above fuels, plus nuclear or wind. An alternative, of course, is solar generated electricity which involves no turbine. So, with electricity the question is always: how is it generated? However, as electricity is transmitted through grid from source to sink, some energy is lost, so there is a small waste factor resulting from that component. The overall loss from utility to end use is 8 – 15%, which means that more energy has to be generated than we use, adding to the production need and emissions at the utility. (http://blog.schneider-electric.com/energy-management-energy-efficiency/2013/03/25/how-big-are-power-line-losses/) . Of course, if the energy source is solar panels on the roof, this does not apply.