Ultimate Solar Panel in Tech Reborn uses sunlight as a source of energy. It should be able to see the sun to generate energy.

This is a Tier 4 solar panel which makes it four times more efficient than it's Tier 3 predecessor.

Ultimate Solar Panel generates 256E/t in the daytime and and 16E/t in the nighttime respectively. It can store up to 512K of Energy.

Panel's energy output can be controlled with redstone.

Ultimate Solar Panel is used to craft Quantum Solar Panel

General information about Tech Reborn solar panels can be found here.