From Starbounder - Starbound Wiki
It triggers a signal for dim light and a signal for bright light to wired mechanisms. It's functionally the same as a craftable light sensor.
|This photovoltaic panel generates electricity as it absorbs solar light.
|This panel draws in energy from the stars to generate power!
|Panel createsss energy from sssunlight. Floran can relate.
|Impressed. This panel absorbs light to create power. If only I was engineered to do this...
|This solar panel creates energy from light. Ancient humans were pretty fond of them, I hear.
|This solar panel generates clean energy from the sun. I imagine it wouldn't be so useful underwater.
|This generates power from solar light? I could earn a tidy livin' just sittin' on it.