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Q & A: why worry about energy conservation?

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Most recent answer: 04/23/2020
Q:
If we can convert energy from one form to another, why are people so concerned about conserving it?
- Luke Lynn (age 15)
De Soto
A:

that's an important question. Energy itself is conserved precisely as a fundamental law of physics (First Law of Thermodynamics), regardless of what we do. So why worry?

The problem is that the Second Law of Thermodynamics says that the forms of energy are changing from the organized types to the disorganized thermal types. What we need to conserve is "free energy", a quantity that takes into account the entropy as well as the enrgy. The Second Law says that entropy keeps going up, which mean that free energy goes down.

Various forms of free energy are stored up on earth, e.g. fossil fuels, whose free energy goes down when they are burned. These could become used up, although the global warming they create will become a huge problem well before we run out. Often, when people say it's important to conserve energy the most immediate reason is that using less energy means burning less fossil fuel and thus reducing the rate of global warming.

Some oher forms of free energy around are the nuclear fuel of the sun and the nuclear fuels of some elements on earth. Solar energy will continue to reach the earth for hundreds of millions of years. We need to harness it more effiiently.

Mike W.


(published on 04/23/2020)

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