How is electricity transported

Electricity is moved from one place to another through copper or aluminium cables running above or below ground. Surface cables are less expensive than underground ones, since they do not need to be insulated, although they do have the disadvantage of disfiguring the countryside. The electricity which leaves the generating station is not taken directly to the consumer, since this would result in considerable losses of energy. The current which travels along the cables produces heat, and this heat increases as the current gets stronger. In order to reduce the loss of power through heat, the strength of the current must be reduced by raising the potential or voltage. For this reason the current first passes through a transformer which raises the potential to 275,000, sometimes 400,000 volts. It can then be led to its destination along high-tension cables running over long distances. On arrival, the voltage is reduced to some 11,000 volts in sub-station. The current then passes along underground cables to the transformer stations which can be found in every residential district. There it is brought down to the standard voltage 240 volts, and enters our homes as low-tension current, which can then be used for lights and domestic appliances.