6.2.4.3 The National Grid. The National Grid is a 1 Describe how electrical power is Video clip Model the National Grid to system of cables and transferred from the power show how electricity is sent YouTube: transformers linking stations to the consumers via the from power stations to stations to consumers. National Grid. Students will need consumers. to be able to give the types of Electrical power is transformer used and describe Demonstrate how transferred from power how the potential difference in transformers work and where stations to consumers using the wires changes at each stage they are placed in the the National Grid. of the process. National Grid. Step-up transformers are How does electricity get from the Demonstrate a of the used to increase the power station to our homes? national grid to show the potential difference from the A large potential difference is effect of transferring energy power station to the dangerous. Why is the electricity at high and low potential transmission cables then sent at a high potential difference differences. step-down transformers are rather than a low p.d.? used to decrease, to a much How do transformers work? lower value, the potential difference for domestic use. What do substations do? This is done because, for a Explain how the National Grid power, increasing the system is an efficient way to transfer energy. potential difference reduces the current, and hence Why is it more economical to reduces the energy losses transfer through the National due to heating in the Grid at high potential differences rather than using lower and transmission cables. potentially safer potential differences?
6.2.4.3 The National Grid. The National Grid is a system of cables and transformers linking stations to consumers. Electrical power is transferred from power stations to consumers using the National Grid. Step-up transformers are used to increase the potential difference from the power station to the transmission cables then step-down transformers are used to decrease, to a much lower value, the potential difference for domestic use. This is done because, for a power, increasing the potential difference reduces the current, and hence reduces the energy losses due to heating in the transmission cables. 1 Describe how electrical power is transferred from the power stations to the consumers via the National Grid. Students will need to be able to give the types of transformer used and describe how the potential difference in the wires changes at each stage of the process. How does electricity get from the power station to our homes? A large potential difference is dangerous. Why is the electricity sent at a high potential difference rather than a low p.d.? How do transformers work? What do substations do? Explain how the National Grid system is an efficient way to transfer energy. Why is it more economical to transfer through the National Grid at high potential differences rather than using lower and potentially safer potential differences? Model the National Grid to show how electricity is sent from power stations to consumers. Demonstrate how transformers work and where they are placed in the National Grid. Demonstrate a of the national grid to show the effect of transferring energy at high and low potential differences. Video clip YouTube:
AQA-8464F-SOW-ELEC.DOCX