[Nimmie (OP)]

Fire can actually cause electrons to flow in a solar cell. I think this is because fire contain photons which just like light from the sun when it hits the solar cell causes electron to flow.

[chiralSPO]

It doesn't matter where the photon comes from, if it has a frequency high enough to activate the solar cell, it will. Typical polycrystalline solar cells will capture all of the visible light, and even some IR, all of which is emitted by flames.

Now, you would need a very big fire to come close to the brightness of the sun (which would be as bright as if you put 10,000 candles in a square foot), and the energy efficiency would be awful...

[evan_au]

The increased temperature of a fire causes solar cells to be less efficient.
You need solar cells to be brightly illuminated, without increasing in temperature (too much).
That is a neat trick, since solar cells are typically dark blue (nearly black), so they absorb almost all photons that strike them.