Reelight a Danish Company has several models. the induction powered LED, gets juice
by the long magnet attached to the spokes., light bracked under the axle lock nut ,
so part of the wheel

moving thru the price-points gets a capacitor added and a steady on light results..
and a wired light you could mount higher than the hub. level..
essentially a hub dynamo with out rebuilding the wheel.., just not quite as bright..
OK for lit city streets.

Have a Schmidt Hub Dynamo and it is the way to go.. can run 2 lights off it ,
+ a taillight.