P1.4~Methods We Use To Generate Electricity

Question 1

What are some non renewable energy resources?

Answer 1

Fossil fuels
~Coal
~Oil
~Gas
Nuclear fuels
~Urainium
~Plutonium

Question 2

Why aren’t nuclear fuels classed as a fossil fuels?

Answer 2

Because it isn’t burnt to release energy.

Question 3

What is nuclear fission?

Answer 3

The splitting of a nucleus releasing neutral that collide with other nuclei, causing a chair reaction which generates huge amounts of heat energy.

Question 4

How is electricity generated from fossil fuels?

Answer 4

Fossil fuels are burnt to release heat energy, which boils water to produce steam. The steam is used to drive turbines, which are attached to electrical generators. A gas jet turbine generator heats air instead of water, giving it a quicker start up time.

Question 5

How was electricity generated from nuclear sources?

Answer 5

A reactor is used to generate heat by nuclear fission. A heat exchanger is used to transfer the heat energy from the reactor to the water, which turns to steam and drives the turbines.

Question 6

What are biofuels?

Answer 6

E.g. Wood and rapeseed oil
They are burnt to release energy. Because the plants used grow relatively quickly, the fuels burned can be replaced.
They are classes as a renewable energy source
Plant and animal waste can also be used for biofuel

Question 7

Advantages of using coal for energy?

Answer 7

Relatively cheap and easy to obtain
Coal fired power stations are flexible in meeting demand and have a quick start time the nuclear equivalent
Estimates suggest that there may be over a century is worth of coal left

Question 8

Disadvantages of using coal as an energy source?

Answer 8

Burning produces carbon dioxide (CO2) and sulfur dioxide (SO2).
Produces more CO2 per unit of energy then boil a gas does (CO2 causes global warming). SO2 causes acid rain on the sulfur is removed before burning all the SO2 is removed from the waste gases. Both of these add to the cost.

Question 9

Advantages of using oil as an energy source?

Answer 9

Enough oil left for the short to medium term.
Relatively easy to find, does the prices variable.
Oil fired power stations are flexible in meeting demand and have a quicker start-up time then both nuclear power and coal-fired reactors.

Question 10

Disadvantages of using oil as an energy source?

Answer 10

Burning produces CO2 and SO2 (CO2 causes global warming, SO2 causes acid rain).
Produces more CO2 than gas per unit of energy.
Often carried between continents and tankers leading to the risk of spillage and pollution.

Question 11

Advantages of using gas as an energy source?

Answer 11

Enough gas left for short to medium term.
Can be found as easily as oil.
No SO2 is produced.
Gas-fired power stations are flexible in meeting demand and have a quicker start time than nuclear, call and oil fired reactors.

Question 12

Disadvantages of using gas as a source of energy?

Answer 12

Burning produces CO2, although it produces less than coal and oil per unit of energy.
Expensive pipelines and networks are often required to transport it to the point of use.

Question 13

Advantages of using nuclear as a source of energy?

Answer 13

Cost and the rate of fuel consumption is relatively low.
Can be situated in sparsely populated areas.
Nuclear power stations are flexible and meeting demand.
No CO2 or SO2 produced.

Question 14

Disadvantages of using nuclear as a source of energy?

Answer 14

Although there is very little escape of radioactive material in normal use, radioactive waste can stay dangerously radioactive for thousands of years and safe storage is expensive.
Building and decommissioning is costly.
Longest comparative start up time.

Question 15

What a general advantages and disadvantages of nonrenewable sources of energy?

Answer 15

Advantages
~Produce huge amounts of energy
~Reliable
~Flexible in meeting demands
~Do not take up much space
Disadvantages
~Pollute the environment
~Causes global warming and acid rain
~Will eventually run out
~Fuels often have to be transported over long distances

Question 16

What are renewable energy sources?

Answer 16

Energy sources that will not run out because they are continually being replaced.

Question 17

How can renewable energy sources be used to generate electricity?

Answer 17

Renewable energy sources can be used to drive turbines or generators directly. In other words, no for your needs to be burnt to produce heat.

Question 18

What are different types of renewable energy sources?

Answer 18

Wind turbines. 
Solar cells and panels. 
Hydroelectric dam.
Tidal barrage. 
Nodding duck. 
Geothermal.

Question 19

How do wind turbines work?

Answer 19

Wind can be used to drive huge turbines, which, in turn, drives generators. Wind turbines are usually positioned in the top of hills so they are exposed to as much wind as possible.

Question 20

How do solar cells and panels work?

Answer 20

Solar cells and panels are made of a semiconductor material (usually silicon), which captures the light energy and transforms it into electrical energy.

Question 21

How does a hydroelectric dam work?

Answer 21

Water that is stored in a reservoir above the power station is allowed to flow down through the pipes to drive the generator, which produces a lot of power.

Question 22

How does a tidal barrage work?

Answer 22

As the tide comes in water flows freely through a valve in the barrage. This water then becomes trapped. At low tide, the water is released from behind the barrage through a gap that has a turbine in it. This drives a generator.

Question 23

How does a nodding duck work?

Answer 23

Nodding ducks are found in the sea. The motion of the waves of the ‘Ducks’ rock and this movement is translated into a rotary movement which, in turn, drives a generator.

Question 24

How does geothermal work?

Answer 24

In some volcanic areas hit water and steam rise naturally to the surface, having been heated up by the decay of radioactive substances (e.g. Urainium) within the earth. This steam can be used directly to drive turbines which, in turn, drive generators.

Question 25

Advantages of wind power.

Answer 25

No fuel and little maintenance required.
No pollutant gases produced.
Once built they provide ‘free’ energy when the wind is blowing.
Can be build offshore.

Question 26

Disadvantages of wind power.

Answer 26

Need many turbines to produce a sizeable amount of electricity, which means noise and visual pollution.
Electricity output depends on the strength of the wind (unreliable)
Not very flexible in meeting demand unless the energy is stored.
Building cost can be high.

Question 27

Advantages of tidal and wave power.

Answer 27

No fuel required.
No pollutant gases produced.
Once built they provide ‘free’, reliable energy.
Barrage water can be released when demand for electricity is high.

Question 28

Disadvantages of tidal and wave power.

Answer 28

Tidal barrages, across estuaries, are unsightly, a hazard to shipping and destroy habitats of wading birds.
Daily variations of tidal and waves affect output.
High initial building cost.

Question 29

Advantages of hydroelectric power.

Answer 29

No fuel requires unless storing energy to meet future demand.
Fast start up time to meet sudden demand.
Produces large amounts of clean, reliable energy.
No pollutant gases produced.
Water can be pumped back up to the reservoir when demand for electricity is low.

Question 30

Disadvantages of hydroelectric power.

Answer 30

Location is critical and often involves damming upland valleys, which means flooding farms, forests and natural habitats.
To achieve net output (aside from pumping) there must be adequate rainfall in the region where the reservoir is.
Very high initial capital outlay (though worth the investment in the end).

Question 31

Advantages of solar power.

Answer 31

Idea for producing electricity in remote locations.

Excellent energy source