Why are Power Lines High Voltage?

This is a good question because we know high voltage lines can be dangerous to people. Why not use low voltage power lines?

The amount of power that is delivered through an electric power line is the product of the voltage and current going through it (Power = Current x Voltage). Thus, high power transmission can be achieved by having either high current or high voltage.

However, a small amount of this power is lost through heating of the power line due to its resistance. The amount of power dissipated by the transmission line is proportional to the current going through it and the square of the resistance (Power Loss = Current x Resistance x Resistance). In order to minimize the heating of the power line, the current must be kept to a minimum.

Therefore, the best way to deliver the most power, and keep loss to a minimum, is to have a high voltage and a low current.