Solar Powered

Solar Powered is a perk in Fallout 3, Fallout: New Vegas and Fallout 4.

Fallout 3 and Fallout: New Vegas
Unlike Night Person, which operates both indoors and out, this perk only operates outdoors. It is in effect between 6 AM and 6 PM. It synergises well with Rad Absorption for healing minor health damage and minor radiation poisoning while exploring or fast traveling.

Fallout 4
Rank 2 heals roughly 4 rads per second, meaning the Sole Survivor can go from the brink of death to completely radiation-free in approximately four minutes.