I have had the same thoughts. My power is meager, and using a couple watts for lighting adds up over a long ride. I'm not going to switch from dynos though.

For headlights, I have considered Outbound https://www.outboundlighting.com/store/ Considering this to replace my Cygolite expillion that I have as a backup headlight.
There are a couple of taillights that I find interesting but I can't remember them right now. But Cygolite hotshots are pretty amazing and you can easily throw one in the bag for a spare.