What is Energy Worth?
Everyone pays attention to -- and often whines about -- the price or cost of energy. I would like to pose a different question: what is the value of energy? What is energy really worth?
It turns out to be a more interesting question than it might first appear. Let me present a few illustrative calculations.
A healthy adult can exert about 100 watts of effort for a reasonably sustained period. (Have you ever worked out strenuously on an exercycle with an output display? If so, have you ever pushed it to over 200 watts for very long?) Thus, over the course of a 10-hour day, a human might produce 1000 watt-hours -- or 1 kilowatt-hour. From your local utility, you probably pay about a dime for a kilowatt-hour. On the other hand, if you were to pay that adult a (low) wage of $5/hour for that degree of effort, that kilowatt-hour would cost $50.
In other words, electricity is priced about 1/500 the equivalent value of human effort.
Oil is even more of a steal. There are 3412 Btu in a kilowatt-hour, meaning that an adult can produce about 3412 Btu of energy effort in a 1o-hour day -- or 341 Btus per hour. In a barrel of oil, there are 6.2 million Btus -- equivalent to over 18,000 man-hours, which would cost over $90,000 at a (low) wage of $5/hour.
At $60/barrel, oil is priced about 1/1500 the equivalent value of human effort.
And we complain that energy is expensive? Try replacing our taken-for-granted energy forms with the work of humans -- and paying a wage for it!
Labels: alternative energy, cleantech, Cleantech Blog, energy, green tech, greentech
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posted by Richard T. Stuebi @ 10:18 AM
10 comments
10 Comments:
Thats a great way to look at it!
I've always felt energy is simply too cheap. That's why people don't bother with conserving it.
In my neighborhood there are plenty of poor people with gigantic trucks.
Logic would say that a really big truck is expensive & if you are poor, you should better spend your money somewhere else.
But reality says... a truck is big & makes me feel powerful. Because I'm poor, I need to feel powerful even more.
I'm moving soon to a more upper class neighborhood. There, most people drive small, economical cars. They have money & so want to be modest.
In the end... it has nothing to do with the price of the fuel. Except that the majority of people don't have money & want to feel their power & so will be against raising the price of oil.
To compare the energy content of oil and steam with how much weight a pour man can carry is worse than comparing apples with oranges. As a mental exercise sound great, but the mankind did not evolved for thousands of years to be compared, worth wise, with a tree that leaved a few billions years ago. People can do many things of immense power with very little physical effort.
Most of us are confused when comparing conventional generation with renewable energy. Your model confuses things further.
Gotta disagree, Nick. This is a fascinating way to relate two energies so very different but, nonetheless, physical energy both. I found it not the least bit confusing, but provocative.
JJ, I expected many to disagree. I am surprise that nobody said: shut up Nick! However, I stand uninspired by the comparison. Respectfuly, Nick
People can do many things of immense power with very little physical effort.well nick why don't you give us some examples. ps remember if they use any tools them tools first have to be made using energy of some form
Yo, Nick.
Confused? Try pushing your car to the store.
Bryan
You see what I mean? I will not push the damn car to the store! I will walk there. Eventually I will eat a $ 0.50 apple to replace the energy consumed. Or even better, I will lose one once from the 100 lb that I carry continuously with me.
P.S. I do not want to be negative. I just feel that this controversy is constructive. Nick
the math is correct, but the actual number is probably lower than that. Only about 25% of our daily caloric needs can be converted to work. That means a healthy adult who needs 2400 calories a day can only produce the heat equivalent of about 600 calories. Life is hard!
My girlfriend has some extra pounds of fat. I think she would pay to get rid of that energy. How will this factor screw upt the math?
We must find ways to conserve energy before its too late. Every little effort we do is big enough to make a change and help preserve our planet.
We must be responsible to take care of our environment or say sorry for what we have done, and the effect could be irreversible.
If you want to know more about helping our environronment, check out these links: Green Cars
and Green Fuels
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