Could be useful making a working van de Graaff could be created by two non-conductive materials sliding against each other because of piston forcing it like that when a conductor material would touch the two materials static electricity would go along the wires
This would likely break saves, if there was an element (say STTK) that when moved by PSTN touching a conductor makes a SPRK, this might not break saves, but +1 for the good idea (yes you can actually vote on forum posts)