An electric current in a tungsten filament results from the drift of electrons. We can understand the electrons’ drift as a result of the acceleration produced by the electric field in the filament. From the energy perspective, we can say that electrons are losing EPE in exchange for KE.
As they drift through the filament, however, the electrons collide with the massive ions of the tungsten metal, and lose their newly gained KE to the vibrational energy of the metal lattice. The tungsten becomes hot and eventually glows. This is how the EPE of the electrons is ultimately converted into heat and light in the filament. Anyway, the way electrons keep losing their energy represents a hindrance to the flow of electric current, and is the origin of electrical resistance.
xmPhysics 