Looking for a SF short story about an atom-wide energy draining alien on a moon

[Dark Stranger]

Hi guys! I'm trying to find a short story about humans who land on a moon and set up a power station, but on top of a massive alien that's miles long, but only an atom wide. It drains the power from the station and when the humans find out and attack it, it drains that power too and it thinks the humans are great for feeding it so much.

It was part of a short story collection, I can't remember anything more about it! It's probably 70s / 80s, I don't think the book was any later than that.