Coils of wire can form inductors... which can generate electrical current when a magnet moves through them or store a limited amount of energy in a magnetic field... but I'm not sure what the lifespan of such storage would be or what the potential power of a discharge would be... but its fairly simple to make one... a wire wrapped around a nail would technically be a crude inductor...
However, is your man friend or foe? If friend... he could be connected to an external generator at a low voltage or current.. and someone with medical knowledge can pick up for me from there... or if he's foe he could fake it... and something happens to turn something on...
On the other hand, we're talking about a world where an alien can look human and fly, a red rock transfered his powers and the cure for ingestion of a radioactive rock was to step in a nuclear reactor... so you can probably argue for some slightly wonky physics, ~.^
