Energy

Question 1

Renewable or infinite energy resources

Answer 1

Are sources of power that quickly replenish themselves and can be used again and again.

Question 2

Wood

Answer 2

Wood can be used for fuel and is renewable if trees are replanted.

Question 3

Biomass

Answer 3

Biomass, which is material from living things, can be renewable if plants are replanted.

Question 4

Coal (fossil fuel) Where it is from

Answer 4

Formed from fossilised plants and consists of carbon with organic and inorganic compounds. It is mined from seams of coal found between layers of rock in the earth.

Question 5

Coal (fossil fuel) Advantages / Disadvantages

Answer 5

Advantages
Coal is a ready-made fuel which is cheap to mine and convert to electricity – it lasts longer than oil or gas.

Disadvantages:
When burned, coal gives off atmospheric pollutants, including greenhouse gases.

Question 6

Oil (fossil fuel) where is it from

Answer 6

Carbon-based liquid formed from fossilised animals. Lakes of oil are found between seams of rock in the earth.

Question 7

Oil (fossil fuel) Advantages / Disadvantages

Answer 7

Advantages:
Oil is a ready-made fuel which is cheap to extract and convert into energy. It is used in industry and transport.

Disadvantages:
When burned, oil gives off atmospheric pollutants, including greenhouse gases. There is a limited supply of oil.

Question 8

Natural gas (fossil fuel) where is it from

Answer 8

Methane and other gases trapped between seams of rock under the earth are released through pipes sunk into the ground.

Question 9

Natural gas (fossil fuel) Advantages/Disadvantages

Answer 9

Advantages:
Gas is a ready-made fuel and relatively cheap. It is used in houses for heating and cooking and is a slightly cleaner fuel than coal and oil.

Disadvantages:
When burned, it gives off atmospheric pollutants, including greenhouse gases. There is a limited supply of gas.

Question 10

Nuclear where is it from

Answer 10

Radioactive minerals such as uranium are mined. Electricity is generated from the energy that is released when atoms from these minerals split.

Question 11

Nuclear Advantages / Disadvantages

Answer 11

Advantages:
A small amount of radioactive material produces a lot of energy, it’s relatively cheap and can last a long time. It doesn’t give off pollutants.

Disadvantges:
Nuclear reactors are expensive to
run and nuclear waste is highly
toxic. Leakage of nuclear materials
can have a devastating impact on
people and the environment.

Question 12

Biomass where is it from

Answer 12

It is generated from decaying plant or animal waste, or organic material and can be burned to provide energy.

Question 13

Biomass Advantages / Disadvantages

Answer 13

Advantages:
It is a cheap and readily available source of energy. If crops are replaced, it can be a long-term, renewable energy source.

Disadvantages:
When burned, it gives off atmospheric pollutants, including greenhouse gases.

Question 14

Solar where is it from

Answer 14

Solar energy uses the energy from the sun. It is harnessed through panels containing solar cells.

Question 15

Solar Advantages / Disadvantages

Answer 15

Advantages:
Clean and renewable form of energy. No greenhouse gases are released during the energy production stage.

Disadvantages:
Limited use in northern countries during the winter months. Not constant. Only produces energy when the sun is shining. Solar farms can take up a lot of
space that could be used for other purposes e.g., agriculture.

Question 16

Wind where is it from

Answer 16

Wind turbines are spun by the power of the wind. The blades of the turbine are connected to a generator which turns kinetic energy into electrical energy.

Question 17

Wind Advantages / Disadvantages

Answer 17

Advantages:
Clean and renewable form of energy. No greenhouse gases are released during the energy production stage. Can be placed offshore reducing the amount of space on land needed for wind farms.

Disadvantages:
Unattractive, noisy, can harm wildlife e.g., birds. Wind speed is not constant and so production can rise and fall.

Question 18

Wave and tidal where does it come from

Answer 18

Tidal -the rise and fall of the tides causes water to move back and forth. This can be used to turn the blades of tidal turbines. Each turbine turns a generator which converts kinetic energy to electrical energy.

Wave power involves placing turbines in the ocean and using the power of the waves to turn a turbine to generate electricity.

Question 19

Wave and Tidal Advantages / Disadvantages

Answer 19

Advantages:
Renewable and reliable form of energy – there will always be waves and tides. No greenhouse gas emissions at the energy production stage.

Disadvantages:
Tidal – Constructing a tidal plant can be very expensive. It is limited to certain geographical locations i.e., coastal areas with a strong tidal range.

Wave – visual pollution (looks unattractive). Technology for this is not yet very advanced.

Question 20

Geothermal where does it come from

Answer 20

Wells are drilled to a geothermal reservoir; this releases steam which is used to turn a turbine to generate electricity.

Question 21

Geothermal Advantages / Disadvantages

Answer 21

Advantages:
Renewable and clean energy source.

Disadvantages:
Limited to certain geographical locations – i.e,. tectonically active areas. Expensive to build geothermal power plants. Groundwater can become polluted.

Question 22

HEP (hydro-electric power) where is it from

Answer 22

Hydropower uses the force of water to turn turbines, creating energy. In order to use the flowing water, we build dams on rivers to hold the water in a reservoir. The water flows through the dam, spinning the turbines and generating energy.

Question 23

HEP (hydro-electric power) Advantages / Disadvantages

Answer 23

Advantages:
Renewable and clean energy source. Reliable energy source.

Disadvantages:
Dams are expensive to build. Areas need to be flooded to create reservoirs. Building dams and reservoirs disrupts riverine environments.

Question 24

Wood where is it from

Answer 24

Obtained from felling trees, burned to generate heat and light.

Question 25

Wood Advantages / Disadvantages

Answer 25

Advantages:
A cheap and readily available source of energy. If trees are replaced, wood burning can be a renewable energy source.

Disadvantages:
When burned, it gives off atmospheric pollutants, including greenhouse gases.

Question 26

How long will fossil fuels last?

Answer 26

Oil 50 years
Natural gas 70 years
Coal 250 years

Question 27

Energy security:

Answer 27

The balance between energy supply (production) and demand (consumption) determines the energy
security.

Question 28

What factors affect energy security

Answer 28

Access to Technology
Better technology has allowed energy sources in remote areas (difficult to reach) such as the North Sea and the Arctic to be exploited.
Technology has made it possible to extract natural gas by fracking.

Physical Factors
The geology of an area determines the location and availability of fossil fuels.
Coal is formed from vegetation laid down and altered by heat and pressure over millions of years.
Natural gas and oil is trapped in rocks. Geothermal energy is produced in areas of tectonic activity like Iceland and the Pacific Rim

Costs of Extraction and Production
Some energy sources are costly to extract. Oil rigs and pipelines require huge investment.
Nuclear power stations are expensive to build.

Political Factors
Political factors affect decisions about which energy source to exploit and from which countries energy can be taken from.
Political instability in the Middle East has meant that many oil-consuming countries are looking for alternative energy sources.

Question 29

Energy supply:

Answer 29

• Some countries have a surplus of energy and others have a deficit.
• Energy is traded to even this out.
• On occasions, energy security has led to disputes and even the possibility of conflict between countries.
• For example, Ethiopia’s Grand Renaissance Dam, which was constructed to generate hydro-electric
  power (HEP), has led to conflict with Sudan and Egypt. The dam collects water, which reduces the flow of the River Nile into Sudan and Egypt.

Question 30

Energy consumption:

Answer 30

• Energy consumption is increasing globally.
• Non-renewable fossil fuels still make up most of the energy use.
• New oil fields have been discovered in countries like China and the USA, which have meant that more fossil fuels are available for use.
• The production of electricity from renewable energy is increasing.
• However, renewables still only make up less than 20 per cent of the world’s total energy use.

Question 31

Why is energy consumption increasing

Answer 31

As countries develop, their demand for energy supplies increases.

An increasing population means lots of extra people needing and using more energy. Many will grow up in an energy starved world.

The increasing use of technology like computers and other electrical equipment means a greater demand for energy. As quality of life increases so does the demand for vehicles, lighting and heating.

Question 32

Fuel wood in DRC

Answer 32

70% of the population in DC rely on subsistence farming and on collecting fusiwood to survive
Villagers have to walk 7k for 3kg of firewood
70% Is transported by cart & 307 on peoples
heads

Causes:
Causes deforestation of DC’s tropical rainforest
Puts DRC’s rare species at risk
Alternative is dung, but it deprives the fields of utiliser, reducing crop yields

Question 33

Energy supply in Iceland

Answer 33

Iceland is often considered the most successful country in the world in terms of its energy mix, as the majority of the country’s energy (85%) is derived from environmentally friendly, renewable sources.
Geothermal energy provides about 65% of energy, the share of hydropower is 20%, and the share of
fossil fuels (mainly oil products for the transport sector) is 15%.

Question 34

Geothermal energy: Iceland

Answer 34

Iceland is located on the Mid-Atlantic Ridge, which makes it one of the most tectonically active places in the world.

Located on Hengill volcano in the South of Iceland, Hellisheidi is the largest geothermal power station
in Iceland and the second largest in the world. Hellisheidi was created to provide heat and power to the capital city, Reykjavik.

Question 35

How is geothermal energy harnessed

Answer 35

To generate energy from geothermal sources water is injected deep underground and returns as steam
(or hot water, which is later converted to steam) to drive a turbine on an electric power generator.

Question 36

Use of geothermal energy in Iceland

Answer 36

Steam fields are used to heat swimming pools, such as Iceland’s famous tourism attraction the Blue Lagoon.

Geothermal energy is also used to heat greenhouses, Iceland is able to produce 60% of its fruits and vegetables due to this.

The main use of geothermal energy is for heating, with the heat being distributed to buildings through extensive district-heating systems.

Reykjavik has the largest district heating system across the globe, and 90% of all households in Iceland are heated by geothermal energy. Pipes under Reykjavik are used to heat homes and water

Question 37

Hydro power: Iceland

Answer 37

Hydro power is harnessed through the use of fast flowing water to turn a turbine to generate electricity.

Glacial rivers and waterfalls are both plentiful in Iceland, making it an ideal location for harnessing
hydropower.

Question 38

Wind power: Iceland

Answer 38

The Atlantic also gives the island a long fetch for wind power. In 2012, two wind turbines were installed in South Iceland.

Icewind is also an Icelandic company that specializes in designing wind turbines that can be used in extreme environments.

Question 39

Advantages of Iceland’s geothermal energy: Iceland

Answer 39

Clean energy - does not lead to air pollution.

Once set up- It’s also relatively inexpensive; savings from direct use can be as much as 80 percent over
fossil fuels.

Creates an energy surplus- there is a proposal to construct a 600-mile power line between Iceland and the United Kingdom to export Iceland’s abundant geothermal power.

If countries like Iceland are able to successfully export their supply of renewable energy to other regions throughout the world, then geothermal energy might prove to be a giant step toward mitigating global climate change.

Geothermal energy can be generated consistently throughout the 24-hour day.

Question 40

Disadvantages of Iceland’s geothermal energy:

Answer 40

Expensive to set up power stations- requires high investments in machinery.

Hellisheidi Power Station plans to increase its number of turbines which will cost $197 million. Construction of a plant & well drilling costs ~ €2-5 million per generated MW of electricity.

The power stations are ugly.

Confined to certain geographical locations.

Release of hydrogen sulphide, a gas that smells like rotten egg at low concentrations

Another concern is the disposal of some geothermal fluids, which may contain low levels of toxic materials.

If not done with adequate care, enhanced geothermal systems can trigger earthquakes, severely affecting land stability & putting nearby areas at risk – potential threat to settlements.