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Q & A: energy and heat in solar cell

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Most recent answer: 06/15/2015
Q:
When you switch a solar cell on, does it cool down? I.e. some of the light is now converted to electricity instead of heat?
- Alex (age 20)
Uk
A:

That's an interesting and correct thought. A solar cell heats up as it absorbs sunlight. If it's not connected to anything, that energy leaks out as heat to the environment. It heats up until that heat leakage equals the energy input from the light. If you connect the cell to a circuit, some of the energy leaves via the electrical current. So it won't have to heat up as much to get the heat leak to equal the energy input.

Since a fairly good commercial cell converts about 10% of the input energy to output electrical energy, it would be a noticeable effect although not large.

Mike W.


(published on 06/15/2015)

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