Chapter 4 - Renewable Energy

Question 1

Main source for most energy on earth

which sources do not originate from sun

Answer 1

radiation from the Sun is the main source of energy for all our energy resources

except geothermal, nuclear and tidal

Question 2

how does the sun produce energy

Answer 2

nuclear fusion of hydrogen to give helium

Question 3

Can we perform nuclear fusion on earth right now?

Answer 3

no. but we’re actively researching how to.

Question 4

2 classifications of energy

Answer 4

renewable
non-renewable

Question 5

Define non-renewable energy

Answer 5

Energy sources that once used, cannot be regenerated

Question 6

Sources of non renewable energy

Answer 6

Chemical energy from fossil fuels
Nuclear energy

Question 7

Define fossil fuel

renewable or non-renewable?
come from the sun?

Answer 7

Fuel that were formed from remains of plants and tiny sea creatures that lived millions of years ago

non-renewable
sun: yes

Question 8

What are the problems with fossil fuel

Answer 8

Waste gas pollute the atmosphere when burnt
High lvls of CO2 which contribute to global warming

Question 9

What is an advantage of using coal (and fossil fuels in general)?

Answer 9

relatively cheap and available widely

Question 10

How do we harvest nuclear energy

renewable or non-renewable?
come from the sun?

Answer 10

Fission - Nuclei of uranium atoms are split

non-renewable
sun: no

Question 11

Problems with nuclear fuels + energy

Answer 11

High lvl of safety standards are needed

Waste from nuclear fuels remains radioactive for 1000s of years.

Nuclear power stations are expensive to build

Nuclear power stations are expensive to decomission

Question 12

Define renewable energy

Answer 12

Energy sources that are continuously regenerated

Question 13

What are the renewable energy sources

Answer 13

Tidal
Wave
Hydroelectric
Wind
Solar
Geothermal
Biofuels

Question 14

What energy sources that use water to generate energy

Answer 14

Tidal
Wave
Hydroelectric

Question 15

What is hydroelectric energy

renewable or non-renewable?
come from the sun?

Answer 15

A lake is filled behind a damn. The water that flows down from this lake turns generators.

renewable
comes from the sun

Question 16

What is tidal energy

renewable or non-renewable?
come from the sun?

Answer 16

Lake is filled when tide comes in and empties when tide leaves. Generators are turned by movement of water

renewable
don’t come from the sun

Question 17

Problems with hydroelectric and tidal energy

Answer 17

Expensive to build
Few areas of the world are suitable

Question 18

What is wave energy

renewable or non-renewable?
come from the sun?

Answer 18

Generators driven by up-and-down motion of waves at sea.

renewable
come from the sun

Question 19

Problem with wave energy

Answer 19

Difficult to build - few devices have been successful

Question 20

What is wind energy

renewable or non-renewable?
come from the sun?

Answer 20

Generators are driven by wind turbines

renewable
comes from the sun

Question 21

Problems with wind energy

Answer 21

Large, remote, and windy landscapes are required

noisy

can spoil landscape

Question 22

What is geothermal energy

renewable or non-renewable?
come from the sun?

Answer 22

Water is pumped down to hot rocks deep underground and then rises as steam to push generators

renewable
sun: no

Question 23

Problems with geothermal energy

Answer 23

Deep drilling is difficult

it is also expensive

Question 24

What is solar energy

renewable or non-renewable?
come from the sun?

Answer 24

Energy radiated from sun is absorbed by solar panels.
Heat energy - heat water up.

Light energy - Have solar cells that deliver an electric current when they absorb energy in light.

renewable
sun: yes

Question 25

Problems with solar energy

Answer 25

Variable amounts of sunshine means variable amount of energy produced

Solar cells are expensive

Question 26

What are biofuels

renewable or non-renewable?
come from the sun?

Answer 26

Fuels made by plant and animal matter

renewable
sun: yes

Question 27

What are biofuels

renewable or non-renewable?
come from the sun?

Answer 27

Fuels made by plant and animal matter

renewable
sun: yes

Question 28

Problem with biofuel

Answer 28

Huge amount of land needed to grow plants for biofuel

Question 29

Few ways to be less wasteful with energy:

Answer 29

Less use of vehicles
recycling materials
Better insulation in buildings - less need for heating in cold countries and vice versa

Question 30

process for generating electricity at a hydroelectric power station

Answer 30

vapour rises
rain falls
collects in lake
water falls
water turns turbine
electricity is generated
PE in water to KE in turbine movement
KE in turbine movement to electrical for turbine

Question 31

Process for generating electricity at a thermal power station

Answer 31

Water is heated in a boiler to produce steam, which pushes turbines that turn generators.

The thermal energy that is used to heat the water comes from either nuclear energy, or from burning fuel such as coal, oil or natural gas.

After the steam passes through the turbines, it is cooled and condensed back into water, so that it can go back to the boiler and the process repeats.