Open shape
022xxx
E5 is the E power chord. Its notes are E and B. No third means no major or minor quality. Mute unused strings carefully.
022xxx
x799xx
Numbers show frets from the low E string to the high e string; x means don't play that string.
Every E and B on the first 12 frets. The filled dots are the root, E. Build your own shape from any nearby group.
Other E chords
Other power chords