Generating Electricity

Question 1

what are the negative effects of different energy resources?

Answer 1

release of substances in the atmosphere

waste materials

noise and visual pollution

destruction of wildlife habitats

Question 2

what are the start up times for different sources?

Answer 2

oil, gas - quick start up and can release more energy during peak times

coal, nuclear - slow start up times, release a constant amount

Question 3

In the National Grid, why do they increase the voltage?

Answer 3

for a given power increasing the voltage reduces the current required and this reduces the energy losses in the cables

Question 4

How do transformers used by the national grid?

Answer 4

step up - increases voltage

step down - decreases voltage

power stations produce electricity at 25k V

the power lines carry electricity at 275k V

homes use electricity at 230 V