The circuit is running on one AA 1.5 volt battery.
A modified 10 watt CFL bulb is being illuminated.
The circuit shown in the video has an error in it.
There is no connection between the transistor base and the circuit negative rail.
A 100pf capacitor can be placed there and Jeanna used one.
I just eliminated it and got the circuit to run with one less part.
Information on her circuit can be found at the Energetic forum under the “Big Joule Thief” thread.
I put these inventions / ideas on this site, they are interesting.