Generating electricity

Question 1

how do fossil fuels work?

Answer 1

they are burnt to heat water and make steam. this steam turns a turbine which then turns a generator making electricity

Question 2

advantages of fossil fuels

Answer 2

• very large amounts of electricity can be generated in one places using coal, fairly cheaply
• can be built almost anywhere

Question 3

disadvantages of fossil fuels

Answer 3

-produces carbon dioxide, which contributes to the “greenhouse effect”
-coal produces sulphur dioxide, a gas that adds acid to rain

Question 4

how does Nuclear power work?

Answer 4

Nuclear fission gives out a massive amount of heat energy. this then heats water to make steam, this steam turns a turbine generating electricity.

Question 5

advantages of nuclear power

Answer 5

-does not produces smoke or carbon dioxide, so it doesn’t contribute to TGHE
- ITS RELIABLE

Question 6

Disadvantages of nuclear power

Answer 6

-Nuclear waste is difficult and expensive to remove
- Nuclear power plants are a target for terrorist attacks

Question 7

how does wind power work?

Answer 7

The wind makes the blades of the turbine spin, this turns a generator inside the head of a wind turbine which makes electricity

Question 8

advantages of wind power

Answer 8

• wind is free, wind farms need no fuel
  -produces no waste or greenhouse gases
  -the land beneath can usually still be used for farming

Question 9

disadvantages of wind power

Answer 9

• the wind is not always predictable
  -some people feel covering the landscape with these towers is unsightly

Question 10

How does geothermal power work?

Answer 10

water is pumped through the ground where there are hot rocks. this water turns into steam, the steam turns a turbine, turning a generating creating electricity

Question 11

advantages of geothermal power

Answer 11

-it does not produce any pollution, and does not contribute to TGHE
-No fuel is needed

Question 12

disadvantages of geothermal power

Answer 12

-there are not many places where you can build a geothermal power station
- Hazardous gases and minerals may come up from underground

Question 13

how does tidal power work?

Answer 13

The tides make sea and ocean water move.
as this water moves it can turn blades on a turbine, as the blades spin they turn a generator inside which makes electricity

Question 14

advantages of tidal power

Answer 14

• once you’ve built it, tidal power is free
  -it produces no greenhouse gases or other waste

Question 15

disadvantages of tidal power

Answer 15

• the environment is changes for many miles upstream and downstream
  -only provides power for around 10 hours each day, when the tide is actually moving in or out

Question 16

how does hydroelectric power work?

Answer 16

water in a lake high up can be released through a pipe and as it falls it makes blades of a turbine spin, which then turns a generator making electricity

Question 17

advantages of hydroelectric power

Answer 17

• water can be stored above the dam ready to cope with peaks in demand
• much more reliable than wind, solar or wave power

Question 18

disadvantages of hydroelectric

Answer 18

• the dams are very expensive to build
• building a large dam will flood very large areas
• finding a suitable site can be difficult

Question 19

renewable energy sources

Answer 19

can be used again and again and will never run out or are easily replaced

Question 20

non renewable energy sources

Answer 20

cannot be used again and will run out in the future , they are not easy to replace

Question 21

the national grid

Answer 21

is a network of power stations, transformers, pylons and cables that reliably distribute electricity to our homes and factories on demand

Question 22

step up transformers

Answer 22

increase voltage so the current is lower and the wires don’t waste heat energy meaning it is more efficient

Question 23

step down transformers

Answer 23

decrease the voltage to a safe level for us to use.

Question 24

voltage at homes

Answer 24

230V

Question 25

voltage at power stations

Answer 25

25,000V

Question 26

voltage at pylons and cables

Answer 26

400,000V

Question 27

How do you calculate energy efficiency

Answer 27

useful energy out/ total energy supplied X 100

Question 28

reliable energy sources

Answer 28

-nuclear power
-hydroelectric

Question 29

efficient energy sources

Answer 29

-wind energy
-solar power
-geothermal energy