National grid

• National grid components

  • Transformers
  • Wires
  • Pylons
• Electricity in the UK is generated from a range of different sources but most of it comes from power stations
• Power stations work by

  Generating loads of heat and then converting that thermal energy into electrical energy
• Electricity demand peaks in the late afternoon and evening when everyone gets home from school or work and starts cooking and watching TV
• To cope with surges in demand, power stations need to have lots of spare capacity and often run at well below their maximum power output
• The national grid has to transmit huge amounts of power
• Equation for power

  Power = Voltage x Current
• High current flowing through a wire generates lots of heat due to resistance, leading to energy loss
• To avoid energy loss, current needs to be kept low, requiring high voltage
• Electricity generated in power stations is increased in voltage using step-up transformers to around 400,000 volts before transmission
• Electricity is transmitted across the country between huge pylons
• Before reaching its destination like a town, the voltage is reduced back down to around 230 volts using step-down transformers
• Lowering the voltage is important because high voltages are dangerous and could damage appliances in houses
• Most electricity is generated in power stations and transmitted through the national grid, consisting of transformers, wires, and pylons. Step-up transformers increase voltage for transmission efficiency, while step-down transformers lower it for safe use