My name-developing strategy (developed due to my umpteen thousand alts on City of Heroes) is basically to do Google searches on topics related to the character's powers and see if I can use, modify, or combine them to make a name. For a character with solar powers, I would search physics terms, astronomy terms, astrophysics terms, and sun gods/solar mythology.
Also, don't forget prefixes like Captain, Mister, Ms., Miss, Commander, etc. and suffixes like Man, Woman, Boy, Girl (or, if you read Legion of Superheroes, Lad and Lass).
A few terms that come up in the searches include Apogee, Surge, Sunburst, Starshine (a name I use for a light-based hero of my own), Celestial, Continuum, Corona, Eclipse, Flux, Equinox, Flare, Halo, Spectrum, Solar, Sunrise, Sunburst, Pulsar.
I like alliteration for combination names, so Captain Continuum, Celestial Commander, etc. work for me.