Energy Resources

Question 1

What is the national grid?

Answer 1

-a giant network of transformers and wires that distribute electricity.

Question 2

What do power stations do?

Answer 2

-they produce thermal energy (by burning fossil fuels or nuclear fission) and convert this to electrical energy.
-the amount of electrical energy produced depend on the demand, at late afternoon people cook/watch TV so need more.
-power stations normally work well below their maximum power output to allow spare capacity.

Question 3

The National Grid has to transmit huge amounts of power, what is the electric power equation?

Answer 3

-P=V x I (power = voltage x current)

Question 4

Why does voltage need to be increased before going out the power station?

Answer 4

-when high current goes through a wire, it generates lots of heat (because of the resistance) meaning a lot of energy is lost.
-so if we decrease current, we need to increase voltage.

Question 5

What is the purpose of a step-up transformer?

Answer 5

-it increases the voltage of the energy produced from the power stations.

Question 6

How many volts is the voltage increased to in a step-up transformer?

Answer 6

-400,000V

Question 7

What is the purpose of the wires?

Answer 7

-they transmit the energy all across the country between huge pylons.

Question 8

What is the function and purpose of the step-down transformer?

Answer 8

-it descreases the voltage back down to 230V.
-voltage has to be reduced as high voltages are dangerous and will blow the appliance up.

Question 9

In the past 200 years, the world consumes huge amounts of non-renewable resources, what are four example of these?

Answer 9

-coal
-natural gas
-oil (all three of these are known as fossil fuels)
-nuclear energy.

Question 10

In the past 50 years, we have been using more renewable resources, what are three examples of these?

Answer 10

-solar
-wind
-geothermal
-tidal
-hydroelectric

Question 11

What are all this energy used for?

Answer 11

-40% is used for transport in cars,trains, planes and ships (which are powered by burning fossil fuels)
-29% is used for domestics, such as cooking and heating (natural gas)

Question 12

What is a fossil fuel and what are the main three?

Answer 12

-a fossil fuel is a hydrocarbon containing material formed naturally in the Earth’s crust from the remains of dead plants and animals.
-coal (solid) , crude oil (liquid) , natural gas (gaseous)

Question 13

Fossil fuels are burned to provide heat. What different ways can this heat be used?

Answer 13

-burned to provide heat for direct use (e.g. cooking)
-to power engines (e.g the internal combustion engines in cars)
-to generate electricity.

Question 14

What are the pros of fossil fuels?

Answer 14

-relatively cheap
-can be used in any conditions (e.g dont require wind or sunshine to work)
-much of our current infrastructure is designed to run using fossil fuels.

Question 15

What are the cons of fossil fuels?

Answer 15

-they’re a limited resource so will run out one day.
-they produce carbon dioxide when burned, which is a greenhouse gas and contributes to global warming.
-they sometimes produce toxic gases when burned, such as sulfur dioxide and carbon monoxide.

Question 16

What is nuclear energy?

Answer 16

-nuclear energy is energy obtained via nuclear reactions, such as nuclear fission reactions in nuclear power stations.
-this energy can be used to generate electricity.

Question 17

What are the pros of nuclear energy?

Answer 17

-nuclear fuels do not produce any pollutants like sulfur dioxide or greenhouse gases like carbon dioxide.
-can be used in any conditions.
-although nuclear fuel is a limited resource, it is very unlikely ton run out for a long time.

Question 18

What are the cons of nuclear energy?

Answer 18

-nuclear fuels are technically a finite resource (although nuclear power stations only use very tiny amounts)
-nuclear power stations produce radioactive waste, which remain harmful for thousands of years if not stored carefully.
-it is expensive

Question 19

What is wind energy?

Answer 19

-wind energy is produced from wind turbines.
-we place them in exposed places where there is strong winds.
-each turbines have generators in them and the kinetic energy porduced is turned into electrical energy.

Question 20

What is solar power?

Answer 20

-directly from sunlight.
-used in watches and calculators.

Question 21

What are the pros and cons of solar and wind power?

Answer 21

-they both have low running costs.
-they don’t damage the environment and get cheaper every year.
-however, they have high upfront costs, making them does produce pollutants.
-they are dependent on the weather and take up lots of space.

Question 22

What is geothermal energy?

Answer 22

-thermal energy generated and stored in the earth’s crust.
-this energy is the same energy that heats hot springs.

Question 23

What are two ways that we can use geothermal energy and explain them?

Answer 23

-directly for heat.
-this is cheaper and involves sending water down to the earth’s crust to get heated up and then bringing it back up to heat our homes.
-generating electricity.
-this involves heating the water for so long until it turns in to steam, this steam turns turbines to produce energy.

Question 24

What are the pros and cons of geothermal energy?

Answer 24

-installing it only damages the environment slightly.
-running it doesn’t produce any pollutants.
-you can only use this source in certain areas with volcanic regions.
-power plants needed can be expensive to build.

Question 25

What are biofuels?

Answer 25

-fuel that’s made from recently living organisms.
-generally come from plants/algae, they lock up the sun’s energy which can then be released later.

Question 26

How are biofuels carbon neutral?

Answer 26

-they release CO2 however they took up this carbon dioxide while they were growing so there was no overrall release of CO2.

Question 27

What are the benefits of biofuels?

Answer 27

-they are a renewable resource, cheap.
-they can be mixed with fossil fuels

Question 28

What is the major problem with biofuels?

Answer 28

-they need somewhere to grow all these plants leading to deforestation which releases CO2.
-furthermore, the harvesting,processing and transport of biofuels require energy.

Question 29

How do hydroelectric dams and tidal barrages work?

Answer 29

-it involves placing a big dam over a sea of water to give higher water level on one side.
-hydroelectric dams trap water that comes from upstream, this area is known as a reservoir.
-tidal barrages trap the water and make use of the tides.

Question 30

How do hydroelectric dams and tidal barrages generate electricity?

Answer 30

-the differences in water levels generate this electricity.
-the difference in heights means that the stored water has a huge amount of gravitational potential energy which can be converted into electrical energy.
-the force of the water pushes the turbines in the dam generating electricity before going back through to the river.

Question 31

What are the pros of hydroelectric dams and tidal barrages?

Answer 31

-they are reliable.
-they produce large amounts of energy with no pollution.
-they have immediate responses to increased demand (especially hydroelectric dams)

Question 32

What are the cons of hydroelectric and tidal barrages?

Answer 32

-they have a big impact on the surrounding environment.
-they often flood huge areas including villages and important habitats.
-they sometimes stop boats and fish from travelling.
-initial set-up is expensive.