The following post contains data extracted from chapter 5 of Richard A. Muller’s book “Physics for Future Presidents”. Richard A. Muller is a professor of physics at the University of California, Berkley and past winner of the MacAuthur Fellowship.
I loved this book because it lays out some very interesting facts that in many cases, seem counter intuitive and because it is written for non-science students.
Before we dive into a few facts, lets define a couple of things so that we understand what the facts are saying.
Energy is a measure of available power.
Power is the rate at which energy is used or released. Power is measured in terms of calories/hour or joules/second.
An interesting observation with respect to energy and power is that a steak has almost four times the energy of TNT. The difference is that TNT releases all of its energy much faster.
Some interesting facts:
- Gasoline contains 15 times the energy of an equal weight of TNT.
- Coal is 20 times cheaper than Gasoline for the same energy.
- Gasoline has 1000 times the energy of an equal weight of flashlight batteries.
- Liquid Hydrogen has 4.5 times less energy than an equal weight of Gasoline.
- Energy from non-recharable batteries costs 10,000 times more than what we get from a wall plug.
It doesn’t take long to realize that gasoline is by far the most compact form of energy storage. Muller notes that it wasn’t a coincidence that the 911 terrorists used oil as their weapon of choice.
The best rechargable batteries contain 1% of the energy of gasoline. The real reason that electric cars are only starting to appear on the market has nothing to do with conspiracies between governments and oil companies. Electric cars require batteries and batteries don’t store enough energy when compared to gasoline. The real question that we should be asking ourselves is “Will electric cars ever really make sense?”
Energy comes in many forms and one of those forms is food. When we compare Gasoline to food it still comes out on top. This does not mean that you should consider drinking Gasoline, that won’t end well. [grin]
By weight, Gasoline has:
- 4 times the energy of a Steak
- 2 times the energy of a chocolate chip cookie
- 1.4 times the energy of butter.
Gasoline is in high demand and wars have been fought to secure its supply. That said, it should be noted that some things do beat Gasoline in energy per pound. These are the sources of energy that we should cultivate for future application.
- Natural gas is 1.3 times better
- Hydrogen gas is 2.6 times better
- Uranium or plutonium fission is 2 million times better
- Hydrogen fission is 6 million times better
- Antimatter is 2 billion times better (but hard to come by)
I’ll close with one more group if interesting facts about the cost of energy. This next list compares the cost per kilowatt-hour for various sources of energy. The list does not include the cost of the plant or power lines that deliver the energy.
- Coal: 0.4-0.8 cents ($40-80 per ton)
- Natural Gas: 3.4 cents ($10 per million cubic feet)
- Gasoline: 11 cents ($3.70 per gallon)
- Car Battery: 21 cents ($50 per battery)
- Computer Battery: $4 ($100 per battery)
- AAA Battery: $1000 ($1.50 per battery)
There are way more interesting facts in this chapter than I could relate in a single post. I highly recommend this book as a way to look at the physics of current days issues. Politicians have a way of winding up the public to rally behind things like global warming, when the physics doesn’t necessarily support their position. See section five of the book…