Power Transmission

- The National Grid carries electricity around Britain - The higher the current in a cable, the greater the energy transferred to the surroundings by heating - This means that high currents waste more energy than low currents. - To reduce energy transfers to the environment, the National Grid uses step-up transformers to increase the voltage from power stations to thousands of volts, which lowers the current in the transmission cables - Step-down transformers are then used to decrease the voltage from the transmission cables, so it is safer to distribute to homes and factories NOTE: The equation for power assumes the transformer is 100% efficient