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Q & A: wood energy

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Most recent answer: 10/22/2007
Q:
What is wood energy, I don’t understand. I’m doing a science report that is 25 pages long and one of my energy sources is wood energy. I’ve looked for hours and I can’t find anything.
- Anonymous (age 11)
Newark Academy, Livingston, NJ
A:
Think about the way you would typically extract energy from wood. You'd burn it, just like you might burn coal or oil or natural gas. The stored energy in the wood is chemical energy, meaning that it can be released by a chemical reaction (burning). It's closely related to those fossil fuel energies, because the chemical energy was formed by photosynthesis, using energy from sunlight as the input.

This business of giving names to all sorts of different energies can get pretty silly sometimes, because you can call the same energy all sorts of different names. We've discused that in other answers.

Mike W.

There are some other small ways wood can store energy -- the big one is the chemical energy. You could just heat up the wood, and then it would have some heat energy (we prefer to call it heat energy rather than wood energy because there isn't anything special about the wood here). You could also flex the wood and it would store energy like a spring does. A bow and arrow work by storing energy in a wooden (well, okay, most are made out of fiberglass these days, but they used to be made of wood) bow which can be relased at a rate which is much quicker than it was put in. The wooden arrow (these too are fiberglass today) has kinetic energy as it flies. A wooden musical instrument has both kinetic and potential energy (similar to a spring's potential energy) as it vibrates. You probably don't want to worry about all of these other things, since there isn't nearly as much energy in these as there is chemical energy which you can transform into heat by burning the wood.

Tom

(published on 10/22/2007)

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