World Energy Consumption: Understanding the Differences in Units

AI Thread Summary
World energy consumption is reported in different units, with energy generated in TWh and primary energy consumed in Mtoe, leading to confusion about the figures. The conversion rate indicates that 12,000 Mtoe equals approximately 139,560 TWh, suggesting that consumption exceeds generation significantly. This discrepancy arises because not all primary energy is converted into electricity, with power plants losing a substantial amount of energy as heat. The discussion clarifies that the primary energy consumption includes all sources, not just fossil fuels, and accounts for energy used in processes like mining and transportation. Ultimately, about 36% of the world's energy consumption is used for electricity generation, highlighting the inefficiencies in energy conversion.
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Today I came across a statistical report of world energy consumption. There was a tab named energy generated and the values were given in TWh. There was a tab named Primary energy consumed and the values were given in Mtoe. I saw that the energy generated by the world is around 20000 TWh and the Primary consumption is around 12000 Mtoe.
My questions are:
1. Why is that the Energy generated and the energy consumed are expressed in two different terms?
2. I came to know that 1Mtoe=11.63TWh, the 12000Mtoe=139560TWh. How come the consumption is so high when the generation is only 20000TWh
 
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Would coal and oil be classified under "Energy Generated"?
 
Does that mean 12000 Mtoe is burned to produce 20000 TWh of energy?
 
Where would the fuel burnt in motor vehicles be categorized in these statistics?
 
Do you mean that they have specified the primary fuel consumed which also includes the fuel used for transportation.
That was an electrical energy statistics report
 
That is my interpretation, though based on scant information. Otherwise, the conclusion is that only 1/7 th of the fuel is converted into electric energy. Maybe they take into account the energy used in mining and transporting the coal, including that as primary consumption?
 
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I was not able to upload the entire file. So, I just cropped it.
Just see whether you'd be able to come to a conclusion from the following data
 

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Wikipedia indicates that world production of electrical power in 2008 was 20,261 TWh while world consumption of energy was 143,851 TWh (12,369 Mtoe). These numbers are consistent with the values specified in the opening post. A better label for that "energy production" tab would have been "electrical power production".

Does this mean that only 1/7 of the world's energy annual consumption is used for the purpose of generating electricity? No. Actually it's about 36%. Power plants aren't 100% efficient; the second law of thermodynamics gets in the way. A good chunk (61%) of the energy consumed in the production of electricity is turned into heat rather than electricity.
 
Fine, I understand. Just one clarification, Does the consumption of energy includes renewable energies such as hydro and tidal or it is just confined to coal and oil.
 
  • #10
Unless the document indicates they excluded some energies, I expect it would be an estimate of energy from all sources.
 
  • #11
Thank You all for the instant replies. :)
 
  • #12
Since you're interested in the subject, here's a link i enjoyed.
It's from 2007 when world use was about a cubic mile of oil per year. They try to put that in some perspective.

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http://www.theoildrum.com/node/2186

It leads to to other interesting links..
 
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  • #13
Informative thread Jim.
 
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