PV Gap

Agnes Said:

Is it only possible to harvest solar power from visible light from the Sun?

We Answered:

The answer to your main question is a hesitant "yes".

From the ground, the higher energy photons do not get to us. They are blocked by the atmosphere. We could use the lower energy photons (infrared or radio) but since they carry a lot less energy, they are far more difficult to "harvest".

Still, using black pipes arranged in a tight circle on your south facing roof, it is possible to heat your pool water: this captures the energy from the visible light AND some energy from the infrared.
Some places use huge mirrors to concentrate sunlight in special ovens: that uses all the available energy in the light (after being filtered by the atmosphere).

However, most panels use photoelectric effect which only works with photons above a certain threshold energy (this was proven by, of all people, Albert Einstein).
If the chemical in the panels only work with blue photons, you could shine a thousand red projectors on the thing (red photons have less energy) and crank up the power until the panel melted from the heat, the red photons would still not trigger the reaction to create electricity.

---

Moon

Moonlight is much weaker than sunlight.

The energy we get from the Sun at ground level is almost 1,000 W per square metre (if the square is held perpendicular to the sun's rays). Most of it in the visible light.
The same square, held perpendicular to the rays of the Full Moon, would intercept almost 0.007 W (= 7 mW).

A lot less at other Moon phases.