1-2% of energy is lost during the step-up transformer from when the electricity is generated to when it is transmitted.
2-4% of energy is lost in the transmission lines
1-2% of energy is lost during the step-down of the transform from the transmission line to distribution.
4-6% of energy is lost during the distribution

https://chintglobal.com/blog/how-much-power-loss-in-transmission-lines/