National Grid

why is the national grid system an efficient way of transferring electrical energy?

it minimizes energy loss as heat during transmission through the use of step up and step down transformers and ensures efficient delivery of electricity to customers

what is the national grid?

the network that connects all of the power stations in the country to make sure that everywhere has access to electricity

what is the equation for power?

power= voltage x current

why does current increase as the demand for energy increases?

Because more power is needed as the demand for energy increases and since power = current x voltage, current and power are directly proportional so current increases as the demand for energy increases as more power is needed to meet this demand

how do we keep current low?

by having a high voltage

explain how electricity travel through the national grid?

- Once the electricity is generated in a power station we have to increase the voltage before sending it across the country via transmission lines. For this we use step up transformers to about 400,000 volts

- The wires then transmit the electricity all across the country in huge pylons

- just before it reaches its destination like a town the voltage must be reduced back down, this time by step down transformers to about 230 volts

why must we decrease the voltage from 400,000 volts to 230V before it reaches our homes?

- it can ruin the appliances in our homes

- high voltage is dangerous

what determines what type of transformer it will be?

the number of coils

when do electricity demands peak during the day?

late afternoon when everyone is back from work and school

what are step down transformers used for?

to decrease voltage and increase current

what are step up transformer used for?

to increase voltage and decrease current

what are transmission lines?

cables or structures that carry electricity over long distances from power plants