Topic 3-The National Grid And Transformers Flashcards
The amounts of electricity consumed over the course of one day and over the course of the year varies in very predictable ways:
1) peak daily consumption is around six o’clock, when people are cooking evening meals
2) overall consumption is higher in the winter than in the summer as people use more electricity for lighting and heating
Why do we need the national grid?
1) reliable, secure energy supply
2) an electricity supply that matches the changing demand during the day and over the course of the year
3) high voltage power lines that connect all the power stations on the consumer
4) electrical substations that control the voltage being supplied to consumer
What are step-down transformers used?
High voltages would be very dangerous if used in homes and offices, so step-down transformers change the electricity to a lower voltage and higher current for use by consumers
What is the national grid designed for?
The national grid is designed to minimised the amount of electrical energy last as heat as it passes down the power lines. The electricity generated at the power stations is changed by step-up transformers to very high voltages but very low current-so that the energy lost as heat in the power lines is very small
What happens when electricity get passed down the lines?
When electrical current passes down a wire, it causes the wire to heat up. The heat energy generated from the electricity then transfers into the surroundings, heating the air up around it. The higher the current, the higher the heat loss.
