I got a set of these LED battery-operated lights last year and they worked out awesomely. They have like 8 different settings so you can change the mood. Good enough to light up the whole canopy. Uses AA batteries. Totally recommended.

http://www.amazon.com/Battery-Operated-Outdoor-Functions-Multi-color/dp/B006IB94BG/ref=sr_1_3?ie=UTF8&qid=1359571268&sr=8-3&keywords=battery+powered+christmas+lights

I use these:

http://www.amazon.com/gp/aw/d/B006IB94BG?pc_redir=1406697824&robot_redir=1

They are pretty awesome. One set of batteries will last all week. They're bright, have a couple of different blinky patterns to suit your mood, and the strand is 25' long. I just ordered a second set for this year.