Power Chords are made using the Root note, and the 5th degree of the scale.
Here is an example on the "C major" scale:
1-2-3-4-5-6- 7
C-D-E-F-G-A-B

Now take the first note[C], and the fifth[G]
and you get a chord named " C5 " or [C Power Chord].

If you use the "C minor" scale:
1-2- 3- 4-5- 6- 7
C-D-Eb-F-G-Ab-Bb

And you take the first note[C] and the fifth[G]
you get the same " C5 " chord

Power Chords do not have Major or Minor Tonality.

Here you can see how the Root note and the fifth degree of the scales, are part of the fallowing chords:

C Major....C-E- G
C minor....C-Eb-G
C sus2.....C-D- G
C sus.......C-F- G
C7...........C-E- G-Bb
Cm7.........C-Eb-G-Bb
etc, etc
Two notes are present in all of those chords, they are {C&G}
the same notes that make the " C5 " or [C Power Chord].