The power from the generating station is stepped up from $11 \,\text{KV}$ to $132 \,\text{KV}$ before it is transmitted in order to minimise the loss of energy in the form of heat in the line wires used for transmission. For a given electric power the currentbecomes low at high voltage $(\because P = VI$ , for a given power $P$ , current $I = \frac{P}{V}$ i.e. higher the voltage, low is the current). Therefore the loss of energy due to heating $( = I^2 Rt)$ in the line wires becomes less.