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Energy Transmogrifier

This area is in progress. When finished, the Energy Transmogrifier will allow you to find processes and devices that convert energy between the input and output forms you specify. For now, here is some information about energy conversion:

Many processes and devices, both natural and man-made, convert energy from one form into another. For example, a flashlight converts chemical energy stored in its batteries to electromagnetic energy, in the form of light.

Conservation of Energy

All of the processes and devices that convert energy from one form to another obey the law of conservation of energy, which states that energy can be neither created nor destroyed. So the total amount of energy is not changed by any of these processes or devices, they only change the form of the energy.

Conversion Efficiency

Most processes and devices are not able to convert all of the energy to the desired form. Usually some of the energy remains in its original form, and some of it is transformed into forms other than that desired. For example, in the flashlight the chemical energy in the batteries is first converted to electrical energy in the wires leading to the bulb. Then that electrical energy is converted to light energy by the bulb. But the wires connecting the battery to the bulb are not perfect electrical conductors. Because they have some resistance to electrical current flow, some of the electrical energy passing through them from the batteries to the bulb is converted to heat. This energy that's converted to heat is not lost, but it's not converted to light, either. Since you use a flashlight to see at night (by producing light), not to keep warm (by producing heat), the heat energy is not useful energy in this case. The conversion efficiency of a process measures the fraction of input energy that is converted to energy of the desired type:

conversion efficiency = output energy of desired form / input energy

In the flashlight example,

conversion efficiency = visible light energy from the bulb / chemical energy from the batteries

Further note about the flashlight:

The electrical resistance of the tungsten coil in the flashlight bulb is much higher than that of the wires between the batteries and the bulb. Because of this, much more electrical energy is used by the bulb than the wires. This is a good thing, because part of the electrical energy used by the bulb is converted into visible light, which is why you use the flashlight at all. However, a large fraction of the electrical energy used by the bulb is converted into light with wavelengths longer than 700 nm. This so-called infrared light is invisible to the naked eye. You can "see" some of it if you're wearing night vision goggles, though! So most of the time, like when you're using the flashlight to find your way around your dark campsite or basement, this infrared light is not useful. But if you're wearing night vision goggles that let you see the infrared light, it is useful. So the conversion efficiency of your flashlight is higher if you're wearing infrared goggles than if you're not! That's a very important thing to remember about conversion efficiency: you have to carefully define your desired energy output form before you can calculate the conversion efficiency.

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