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calculating energy usage

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I'm trying to figure out the energy consumption per person per day in the US, but I think I'm messing my dimensional analsys up somewhere. Whoever figure it out first gets a cookie! :embarass:

 

In 2001 the USA used 96275 trillion BTUs of energy that year. This comes to 3.22 trillion watts expended annually or 8.82 billion watts each day .

 

Now there are about 295 million people in the US, so this comes to about 30 watts per person per day ..... wait this can't be right.... Am I doing this wrong, or is my data bad?

A Watt is a unit of power, which is a rate of energy consumption. BTU is a unit of energy. The BTU per year conversion gives you Watts, not Watts per year. You have divided by 365 when you shouldn't have.

  • Author

Ah, I see. I knew I messed something like that up.

 

BTU and Joules convert directly...

 

A watt is a Joule/ second....

 

 

So fixing my math....

 

In 2001 the USA used 96275 trillion BTUs of energy that year. This comes to 3.22 trillion watts.

 

Now there are about 295 million people in the US, so this comes to about 11KW watts per person at any given time.

  • Author

Thanks, I'm getting my numbers together to start a thread on solar power. This these will come in handy.

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