Answer:
The answer to your question is Thermal energy
Step-by-step explanation:
When converting to electrical energy, some equipment is needed, like generators, transformers, cables, circuit breakers, and every kind of devices with specific functions to have a good and safe electrical service. Each device has an internal resistance that opposes the flow of current. The resistances produce thermal energy as a result of current flowing through them. It's not possible to avoid this waste of energy, electrical engineers do their best to use better materials and configurations to reduce the thermal waste to a minimum.
I hope this helps and have a wonderful day!