O2 Concentrator instead of O2 tank

Does anyone use an oxygen concentrator to supply pilot and passengers
in a light plane flying over 14000 feet? A quick google did not turn
up anything but home units and a recent ruling that they can be used on
commercial airlines, but I did not find anything about their use on
private planes.

They don't require more than about 100 watts, so an aircraft electrical
system could keep them going as long as the engine was running.
Internal batteries would keep it alive in an emergency.

Seems like a nice solution to elimination of messing with refilling
tanks.

tom