Final answer:
National grid distributes electricity at 132,000 volts to minimize power loss in transmission lines and ensure safe residential and commercial use.
Step-by-step explanation:
Power is distributed over large distances at high voltage to reduce power loss in the transmission lines. The voltages generated at the power plant are stepped up by passive devices called transformers to 330,000 volts (or more in some places worldwide). At the point of use, the transformers reduce the voltage transmitted for safe residential and commercial use.
For example, electric power is usually generated at greater than 10 kV and transmitted long distances at voltages over 200 kV to limit energy losses. Local power distribution to neighborhoods or industries goes through a substation and is sent short distances at voltages ranging from 5 to 13 kV. This is then reduced to 120, 240, or 480 V for safety at the individual user site.
By transmitting electricity at higher voltages, the current can be minimized, reducing resistive heating and power losses. This is important for efficient distribution of electricity over long distances.