Global energy budget and use The total flow of energy throug

Global energy budget and use:

The total flow of energy through electricity production (“Electricity”) is indicated to be 172.3 EJ/year. You can confirm this is equal to all the sources of energy contributing to electricity production (e.g., “solar and other”, “wind”, “geothermal”, “biomass”, …, “coal”, etc.), though the numbers don’t precisely equal one another due to round-off error. Similarly, the flow of energy coming out of the electrical generation process also equals 172.3 EJ/yr, except for another small difference due to round-off error. The “combined heat and power” is energy that would otherwise be lost, but is instead captured to power industrial processes and also (mostly) to heat buildings.

3) Answer the following questions using the figure above

a). A number of the potential “wedges” proposed by the Princeton Carbon Mitigation Initiative (see especially M9L3) include developing a prominent role for hydrogen and “Synfuels”. Based on the figure here, how close are we to making hydrogen and “Synfuels” a significant contributor to world energy supply? Support your answer using numbers.    (5)

b) What percentage of energy use by transport is accomplished using electricity? (3)

c). What percentage of energy use by transport is accomplished using “Synfuels”? (3)

d). What percentage of energy use by transport is accomplished using gas? (3)

e). What percentage of energy use by transport is accomplished using oil? (3)

f) Assume that everything else remains the same, but that the electricity production is fully (100%) converted to sources which have no carbon dioxide emissions. In other words, assume the current flows of energy from coal, gas, and oil used to generate electricity are switched off and replaced by an equal amount of electricity production from non-emitting sources. Estimate how much carbon dioxide emissions would remain from other (non-electrical) uses, using any appropriate approximations or simplifications. In addition to calculating a final number, explain the process you used to come up with your rough estimate. (10)

Solution

B) 75%

C) 60%

D) 82%

E) 57%