The National Grid

Here is an experiment you should have seen in class. When the bulb is close to the power supply it is bright. When the electricity has to travel some distance to get to the bulb then the bulb is dim. Energy has been lost in the transmission process. If you were to feel the transmission wires they would be warm showing that energy is lost as heat in these wires.

There is a very effective way of reducing the amount of energy lost and that is to transmit the electricity at very high voltages.

By making the voltage bigger with a transformer the current needed in the transmission wires is much smaller. Because of this they don't get as hot and so less energy is lost. The whole process is much more efficient. the voltage is stepped down again to safe values before the electricity is used.

The National Grid is a network of electricity carrying cables that link together power stations and consumers across the country. Notice at what voltages the electricity is produced, transmitted and delivered to our homes.