Sigil of storm battlefield which says recycle a rune when you conquer. When you do this do you still gain the power from recycling it? Floating?

No — recycling the rune for Sigil of the Storm does not add Power to your pool; the Recycle action itself produces nothing.

Power only comes from activating a rune's own ability "Recycle this: [Reaction] — Add [C]" (Rule 164.2.b) — and that consumes the rune, so you can't get Power from the same rune Sigil recycles. What you can do: tap the rune for Energy first (FAQ 2810), then recycle that same rune for Sigil's trigger — the floated Energy stays in your pool for the turn. If you instead recycle a rune via its ability to bank Power, Sigil still needs a different rune to recycle; if you have none left, its trigger simply does nothing (FAQ 6863).