Why is electrical power transmitted at high voltage and low current?
1 Answer
Power loss in transmission lines is given by:
$$
P_{\text{loss}} = I^2 R
$$
where $I$ is the current and $R$ is the line resistance.
- If power is transmitted at low voltage, the current is high, leading to large losses.
- By transmitting at high voltage, current is reduced, which minimizes $I^2R$ losses and improves efficiency.
Thatβs why power plants step up voltage (e.g., 11 kV to hundreds of kV) using step-up transformers for transmission, and then step it down near consumers for safe distribution.