Of the very little we've actually SEEN of Fallout: New Vegas, at least two images have been of sources of green energy. From what we know, the Hoover Dam (Hydroelectric) will make an appearance, as well as Helios One (Solar). The Fallout series has always had political and social undercurrents (though often more in a snide, cynical sort of way than a preachy soap box sort of way), so should we expect a similar running commentary? What would you like to see?
Edit: And before anyone points this out, I'm aware that the Hoover Dam is a carry over from Van Buren, doesn't mean it can't be milked for a little Zeitgeist.