National Grid and cost of electricity Flashcards
What is the national grid?
A network of pylons cables and transformers that allow electricity to be distributed over Britain
What does the national grid allow to happen?
It allows power to be generated and supplied anywhere on the grid
What are two options to be able to transmit the huge amount of power needed?
Increase current
Increase voltage
What is the problem with increasing the current?
High current means a lot of energy is lost through heat in the cables so it’s cheaper to boost the voltage
What are transformers used for?
To step the voltage up at one end for efficient transmission and step it down at the other end to a safe level
What are the two types of transformers?
Step up transformers
Step down transformers
What are the benefits of underground cables?
Less maintenance
More reliable
Not affected by weather
What are the negatives of underground cables?
Expensive
Hard to access
Hard to set up and disturbs land
What are the benefits of overhead cables?
Cheaper
Easy to access and set up
Minimal land disturbance
What are the negatives of overhead cables?
Lots of maintenance needed
Affected by weather
Less reliable
What does the amount of energy transferred by an appliance depend on?
It’s power (how quick it transfers energy) and the amount of time it’s on for
What is a kilowatt hour?
The amount if electrical energy used by a 1kW appliance in one hour
What is energy usually measured in?
Joules
What is power usually measure in?
Watts or kilowatts
What are the formulas for cost of electricity?
Number of units used = power X time
Cost= number of units X price per unit
