The ESL bulbs generate light by firing electrons to stimulate phosphor, and the whole setup is encased in normal light-bulb glass.

Lamp holder and lamp holder: The lamp holder of common bulb and bulb glass case fall off easily below high temperature circumstance.

An incandescent bulb, made of a wire filament encased in glass, emits only 5% of the energy it consumes as light; the rest is wasted as heat.