Most of the powerlines here are underground, except for the ones that run along A1A right in front of where I live haha.
If they're the big high-tension feeder lines on the big steel towers, go under them at night holding a flourescent tube (just the tube, you don't need a fixture) and watch it glow from induction. The lower the wattage of the tube, the brighter it will glow, those little twisty CFL bulbs work too.