3.5 Energy

Question 1

Non-renewable energy

Answer 1

energy that can not be reproduced in the time that it takes to consume it
e.g. coal

Question 2

Renewable energy

Answer 2

energy that is naturally occurring and potentially infinite

Question 3

Fossil fuels

Answer 3

any combustible organic matter that is made from the remains of former flora and fauna

Question 4

Raw material

Answer 4

unprocessed material

Question 5

As countries develop, why do their sources of energy change?

Answer 5

• greater concern for the environment
• rising prices of fossil fuels
• the knowledge that fossil fuels are finite
• aim to reduce reliance on fossil fuel exporting countries
• improvements in renewable technology
• better technology and increased stability allowing nuclear developmemt

Question 6

advantages + disadvantages of coal

Answer 6

ads:
- Energy production using coal can be increased or decreased according to demand
- The technology to burn coal to generate electricity already exists

disads:
- Coal is finite so will eventually run out.
- Many existing reserves are becoming harder to extract or are in environmentally sensitive areas
- Coal releases large amounts of greenhouses gases when burnt
- Mining deep underground coal is very dangerous
- Coal is very baulky and expensive to transport around the world

Question 7

advantages + disadvantages of oil

Answer 7

ads:
- Energy production using oil can be increased or decreased according to demand
- The technology to burn oil to generate electricity already exists
- Technology is improving to extract deeper reserves as well oil in tar sands (Canada).

disads:
- Oil is finite so will eventually run out
- A lot of oil is located in politically unstable countries or environmentally sensitive areas e.g. Libya and Iraq.
- Oil can cause widespread pollution when spilt
- Oil releases large amounts of greenhouse gases when burnt
- Oil is vulnerable to large scale changes in its price
- The production of oil refineries is expensive

Question 8

advantages + disadvantages of gas

Answer 8

ads:
- Energy production using gas can be increased or decreased according to demand
- The technology to burn gas to generate electricity already exists
- Burning gas releases less greenhouses gases then coal and oil
- It is now possible to compress gas and transport it more easily.

disads:
- Gas is finite so will eventually run out
- A lot of gas is located in politically unstable countries or environmentally sensitive areas.
- Gas is vulnerable to leaks and explosions

Question 9

advantages + disadvantages of solar power

Answer 9

ads:
- It is a clean form of energy
- It is a infinite resource
- Panels can be used locally e.g. on top of someones house
- It can be used to heat water and generate electricity.

disads:
- It is expensive to make solar panels
- The sun does not shine all the time
- Not every country gets adequate levels of sun
- They can’t be used at night
- It is hard store surplus energy
- Supply does not always equal demand

Question 10

advantages + disadvantages of wind energy

Answer 10

ads:
- It is a clean form of energy
- It is an infinite resource
- It can be used on a local scale e.g. in your back garden
- Technology is proven
- They can be placed at sea on in mountains away from settlements

disads:
- Visual pollution
- Noise pollution
- Wind is unreliable
- They are expensive to install, especially offshore
- It is hard to store surplus energy
- They have to be turned off in very strong winds

Question 11

advantages + disadvantages of tidal energy

Answer 11

ads:
- It is a clean form of energy
- It is an infinite resource, tides happen twice a day.
- Ideal for island countries.

disads:
- It can block important shipping routes
- May interfere with some animals e.g. sea otters and seals
- Limited number of sites
- Useless for landlocked countries
- High start up costs. - The technology is still being developed
- May be damaged by tropical storms

Question 12

advantages + disadvantages of wave

Answer 12

ads:
- It is a clean form of energy
- It is a infinite resource
- Ideal for island countries.

disads:
- Again it can block shipping routes and interfere with animals
- Again not suitable for landlocked countries
- The strength of waves can vary
- May be damaged by tropical storms
- The technology is still being developed.

Question 13

advantages + disadvantages of hydroelectric power

Answer 13

ads:
- It is a clean form of energy
- It is finite as long as rivers are managed properly.
- The built dam can also prevent flooding.
- The reservoir behind the dam can be a store of water.

disads:
- Only a limited number of suitable rivers
- Can hamper navigation up and down river
- Reservoirs may force resettlement
- Migration patterns of animals maybe disrupted
- Dams reduce the deposition of alluvium downstream
- Dams can flood large areas of land.

Question 14

advantages + disadvantages of biofuels

Answer 14

ads:
- It is a renewable form of energy as long as people replant crops.
- It is cheap and the resources can be grown locally

disads:
- It can still release greenhouse gases.
- Areas can be deforested to grow crops for energy generation.
- If crops are used for energy production it can lead to an increase in food prices.

Question 15

advantages + disadvantages of geothermal

Answer 15

ads:
- It is a clean renewable form of energy.
- It is a finite resource.
- Can be used to heat water and generate electricity.
- Geothermal energy can be created constantly and is not dependent on the weather.

disads:
- Not every country has geothermal potential.
- Installation and start up costs are expensive
- Drilling can release harmful gases.
- Geothermal activity can change which can make the production of energy harder

Question 16

advantages + disadvantages of nuclear power

Answer 16

ads:
- The technology to make nuclear power already exists.
- There is a plentiful supply of uranium, enough to last hundreds of years.
- Nuclear energy releases very low amounts of greenhouse gases.
- It reduces the dependency on oil, coal and gas producing countries
- Nuclear waste can be safely stored underground
- The supply of electricity can be altered depending on the demand.

disads:
- There is always the risk of nuclear accidents like the Chernobyl accident in the Ukraine
- There is a risk that nuclear power stations will become terrorist targets or that nuclear material will fall into the hands of terrorists.
- Countries can use nuclear technology to make nuclear weapons. North Korea and Iran have both been accused of doing this.
- Transporting nuclear material and nuclear waste is risky and expensive.
- Nuclear power stations only have a limited life period and the cost of decommissioning them is expensive.
- There is a belief that living next to nuclear power stations can increase the risk of cancers (leukemia).
- People don’t want nuclear power stations built near where they live
- Mining for uranium is dangerous and can be polluting.
- Nuclear waste remains radioactive for thousands of years (it has a very long half life)

Question 17

disadvantages of fuelwood

Answer 17

• Deforestation
• Biodiversity loss (vegetation is removed and animals lose their home)
• Desertification and reduced rainfall
• Increased soil erosion and increased sandstorms
• Increased time spent looking for wood
• Children taken out of school to look for wood
• Dangers posed by collecting wood (wild animals and criminals)
• Dangers of breathing in smoke inside houses
  Risk of fire within houses

Question 18

Name an energy supply in a country or area.

Answer 18

Hoover Dam - Nevada / Arizona
- Constructed in 1936

Uses

• Generate power / electricity: 4 billion kilowatt-hours of power each year
• Flood control
• Water storage
• Regulation
• The world’s largest hydroelectric installation

Impacts:

• Known to change the water flow, results as a large impact on the Colorado River Delta. Also declines the estuarine ecosystem - no water reached the mouth of the Lake Mead for six years after the construction
• Threatens many species in the area, including plants and animals. It endangers fish.

Question 19

Name a changing energy use.

Answer 19

changing energy use in the UK (1940 - present)

in 1950s:

• main source of energy was coal: huge reserves in South Wales, the Midlands
• stood around 70% of energy was supplied by coal

1960s

• reliance on coal dropped to a total of 34%
• british reserves began to decline and coal became more expensive to extract

1990s
- nuclear production: around 26% of UK’s energy was produced

current:
- 9 operational nuclear power stations producing about 15% of energy
- 45 gas fired power stations producing about 43% of the UK’s needs
- in 2011: UK had 296 wind farms and over 3,400 turbines
- by 2020 the UK aims to produce about 15% of its energy from from renewables