Generating Electricity e the need for the National Grid as an electricity distribution system including power use and responding to changing demand.

How does the national grid cope with demand 1.What is the engineer waiting for? 2.What is going to cause the increase in demand for electricity? 3.What is a TV pick-up? 4.What does the line for the frequency need to stay close to to maintain the power in the national grid? 5.What does the engineer do when the electrical demand increases? 6.How does he respond to the shortfall in energy?

Energy is lost as heat due to the high resistance and length of the cables. Energy wasted in the wire = current 2 (I 2 ) x resistance (R) The higher the current the more energy that gets wasted as heat. Power (w) = volts (v) x current (I) In power cables the voltage is very high and the current very low. This means that less energy is wasted as heat as it travels along the cable. The National Grid

How does the load vary during the day? Time (24 hr clock)Demand (MW) Time (24 hr clock)Demand (MW) 1 35, , , , , , , , , , , , , , , , , , , , , , , ,000

The National Grid Mains electricity is produced by ______________. Generators produce a ___________ by a process called _____________________ induction. When a ___________ is moving into a coil of wire, a voltage is ___________ across the ends coil. If the ends of the ______ are connected to make a closed _________, a _________ will flow round the circuit. If the magnet is moving _____ of the coil, or the other pole of the magnet is moving into it, there is a voltage induced in the ____________ direction. MagnetVoltageOppositeOutGeneratorCircuitElectromagneticCurrentInducedCoil Charles Merz opens the first UK major ___________ ____________ in In 1933 the Central Electricity Board sets up the UK’s first nationwide __.___. grid. The grid is updated in 1965 by adding 400kV _______. ELECTRICITY CANNOT BE ___________ ! Power = Potential Difference x ____________ X 100 __________ = Energy usefully transferred Total energy supplied kV: ________________ GW: ________________ TWh: _______________ EJ: _________________ Hz: _________________ Mains supply to our homes is __________ volts. Mains __________ is in a.c. supply. A ______________ can change the size of an alternating __________. Mains electricity is produced by ___________. The number of GW (1.3 EJ) used annually in the UK is ______ TWh. Voltage of electricity produced in ________ _________ is about 23kV. Transformers either ________ or ________ the voltage. First nationwide _________ grid ran at 132kV, 50Hz. UK National Grid Plenary