Renewable Energy Resources

Question 1

Name 2 advantages of renewable energy resources (compared with non-renewable)

Answer 1

1. They can be replaced faster than they are used up; they won’t run out
2. They do less damage to the environment

Question 2

Name 2 disadvantages of renewable energy resources

Answer 2

1. Generate less electricity than non-renewables
2. Some are unreliable because weather dependent

Question 3

What does wind power involve?

Answer 3

Putting up lots of wind turbines in exposed places e.g. moors, round the coast, off the coast…

Question 4

How is electricity generated by wind turbines?

Answer 4

The electricity is generated directly form the wind turning the blades, which turn the generator inside the turbine

Question 5

Name 4 advantages of wind power

Answer 5

1. No pollution produced (except a bit when being manufactured and set-up)
2. Renewable so won’t run out
3. No fuel costs and minimal running costs
4. Do not leave permanent damage to landscape

Question 6

How many wind turbines do you need to replace a coal fired power station?

Answer 6

1 500

Question 7

What does the fact that it takes 1 500 wind turbines to replace one coal-fired power station tells us about wind power?

Answer 7

1. It generates less electricity than coal-fired power
2. That amount of turbines in one place will spoil the view if farm is on land

Question 8

Name 5 disadvantages of wind power

Answer 8

1. They can be an eyesore
2. They can be very noisy which can annoy local people
3. Weather dependent - unreliable
4. Weather dependent - impossible to increase supply even if demand increases
5. Initial costs are quite high

Question 9

How do solar cells generate electricity?

Answer 9

By generating electric currents directly from the sunlight

Question 10

What are solar cells often the best source of energy for (2), and why?

Answer 10

1. Watches
2. Calculators

Don’t use much electricity

Question 11

Where is solar power often usde and why?

(example)

Answer 11

In remote places (e.g. the Australian outback), because the remote nature of the place measn there’s not much choice in electrical sources

Question 12

Solar power is often used to power ____ ____ ____ and ____

Answer 12

Solar power is often used to power electric road signs and satellites

Question 13

Name 5 advatages of using solar energy

Answer 13

1. No pollution (although quite a lot of energy used to manufacture them in first place, which would create pollution)
2. Very reliable source of energy in sunny countries in day time
3. Also can be cost-effective in cloudy countries like UK
4. Free energy
5. Running costs very low

Question 14

Solar cells are usually used to generate electricity on a ____ ____ ____ e.g. powering ____ ____

Answer 14

Solar cells are usually used to generate electricity on a relatively small scale e.g. powering individual homes

Question 15

Why is it often not practical and too expensive to connect solar cells to the National Grid?

Answer 15

The cost of connecting them to the National Grid can be enormous compared with the value of the electricity generated

Question 16

Name 3 disadvanatages of solar power

Answer 16

1. Large amount of energy used to manufacture them causes damage to environment
2. High initial cost
3. Not practical and too expensive to connect to National Grid

Question 17

Water can be used to ____ ____ in the same way as ____

Answer 17

Water can be used to turn turbines in the same way as wind

Question 18

Wherever water is moving, we can transfer its ____ energy into ____ energy

Answer 18

Wherever water is moving, we can transfer its kinetic energy into electrical energy

Question 19

Name 6 advantages of using hydroelectric power

Answer 19

1. No pollution in running it
2. It can provide an immediate response to an increased demand in electricity (low start-up time)
3. Reliable (except in times of drought - but Great Britain = not really a problem)
4. No fuel costs and minimal running costs
5. Useful way to generate electricity on a small scale in remote areas
6. Renewable

Question 20

Name 4 disadvantages to hydroelectric power

Answer 20

1. Rotting vegetation releases methane and CO₂
2. Possible loss of habitat for some species (sometimes loss of whole villages)
3. Can be an eyesore when they dry up
4. High initial costs

Question 21

How can we reduce the impact of hydroelectric power on humans?

Why?

Answer 21

By putting them in remote valleys

• Reduces likelihood of ugliness being seen
• Reduces chance of villages having to be lost

Question 22

Hydroelectric power usually requires what?

Answer 22

The flooding of a valley by building a big dam

Question 23

Very simply, how does hydroelectric power work?

Answer 23

Rainwater is caught and allowed out through turbines

Question 24

Name the 4 steps to generating electricity at a hydroelectric power station, and the useful energy transfers

Answer 24

1. Water stored in reservoir at top of valley by dam

Gravitational potential

2. Water released down hill

Kinetic

3. Flows through turbines, turning them
4. Turbines connected to generator - generates elecricity

Electrical

4. Connected to National Grid - to places that need it e.g. homes

Question 25

What does 'pumped storage' do?

Answer 25

Gives **extra supply** of energy just when it is **needed**

Question 26

Most large power stations have huge boilers that have to be kept running ____ \_\_\_\_, even though ____ is very \_\_\_\_. What does this mean?

Answer 26

Most large power stations have huge boilers that have to be kept running **at night**, even though **demand** is very **low**. This means there's a **surplus** of energy at **night**

Question 27

Pumped storage is one of the best solutions to what?

Answer 27

**Storing** spare energy for **later use**

Question 28

How does pumped storage work?

Answer 28

1. Surplus **night-time electricity** is used to **pump** water up to a **higher reservoir** 2. This can then be **released quickly** during periods of **peak demand** such as _teatime_ each evening, to supplement the **steady delivery** from the big power stations

Question 29

How does pumped storage differ from hydroelectric power?

Answer 29

It uses the same idea BUT **_isn't_** a way of _generating_ power - it's simply a way of **storing** energy that has **already** been generated

Question 30

How much of the electricity in Britain comes from hydroelectric power

Answer 30

Only a very **small percentage**

Question 31

In the last few years, how much of Norway's power has been generated using hydroelectric power?

Answer 31

99%

Question 32

How does wave power work? | (2 steps)

Answer 32

1. You put lots of small **wave-powered turbines** along the **coast** 2. As waves come into the shore they provide an **up and down motion** which can be used to **drive a generator**

Question 33

Name 4 advantages to wave power

Answer 33

1. **No pollution** 2. **No fuel costs** and **minimal running costs** 3. Can be very useful on **small islands** 4. **Renewable**

Question 34

Name 5 disadvantages to wave power

Answer 34

1. **Spoils the view** 2. **Hazard to boats** 3. Fairly **unreliable** as waves tend to die out when the wind drops 4. **Initial costs are high** 5. **Unlikely** to provide energy on a **large scale**

Question 35

What are tidal barrages?

Answer 35

**Big dams** built across **river estuaries** with **turbines** in them

Question 36

How do tidal barrages work?

Answer 36

1. As the **tide comes in** it fills the estuary to a height of **several metres** and **drives the turbines** 2. This water can be allowed out **through the turbines** at a controlled speed

Question 37

What is the source of energy for tidal power?

Answer 37

The **gravity** of the **Sun** and the **Moon**

Question 38

Name 6 advantages of tidal power

Answer 38

1. **No pollution** 2. Pretty **reliable** - tides come twice a day and always near to predicted height 3. Excellent for **storing** energy ready for periods of **peak demand** 4. **No fuel cards** and **minimal running costs** 5. **Potential** for generating a **significant amount** of energy 6. **Renewable**

Question 39

Name 6 disadvantages of tidal power

Answer 39

1. **Prevent** free **access** by boats 2. **Spoil the view** 3. **Alters** the **habitat** of wildlife 4. **Height** of the tide is **variable** - significantly _less power_ from _lower tides_ 5. **Don't work** when water level is **same on both sides** - happens _4 times daily_ 6. **High initial costs**

Question 40

What is a very simple definition of geothermal energy?

Answer 40

**Heat** from **underground**

Question 41

Where is geothermal energy only possible?

Answer 41

In **volcanic areas** where **hot rocks** lie quite near the **surface**

Question 42

What is the source of much of the heat in geothermal energy?

Answer 42

The **slow decay** of various **radiotactive** elements, including **uranium**, deep inside the Earth

Question 43

How does geothermal energy work? | (5 steps)

Answer 43

1. **Underground heat** is caused by _radioactive_ elements _decaying_ 2. We **pump cold water** down to the hot rocks 3. This **heats** the water 4. _Hot water_ and _steam_ **rises** to the surface 5. It is used to turn a **turbine** which drives a **generator**

Question 44

Name 2 advantages of geothermal energy

Answer 44

1. **Free** energy 2. **Renewable**

Question 45

What is being done in some places with geothermal energy?

Answer 45

Geothermal heat is used to **heat buildings _directly_**, _without_ being converted to **electrical energy**

Question 46

Name 2 disadvantages to geothermal energy

Answer 46

1. **Aren't** very many **suitable locations** for power plants 2. The **cost of building** the power plant is often **high** compared to the amount of **energy** we can get **out** of it

Question 47

How do we use biofuels to generate electricity

Answer 47

In exactly the same way as fossil fuels: 1. Burn 2. Boil 3. Turn 4. Generate

Question 48

How else are biofuels used like fossil fuels?

Answer 48

Used in some cars

Question 49

What states can biofuels be?

Answer 49

Any - solid, liquid, or gas

Question 50

Name 3 examples of solid biofuels

Answer 50

1. Straw 2. Nutshells 3. Woodchips

Question 51

Name 1 example of a liquid biofuel

Answer 51

Ethanol

Question 52

Name an example of a gaseous biofuel

Answer 52

**Methane**'**biogas**' from sludge digesters

Question 53

Where are sludge digesters used?

Answer 53

In sewage processing

Question 54

Where can we get biofuels from (2)?

Answer 54

1. From _organisms_ that are still **alive** 2. From **dead** _organic_ matter - like fossil fuels, but from organisms that have been **living** much more **recently**

Question 55

How do we get ethanol?

Answer 55

By **fermenting** crops like **sugar cane**

Question 56

What can plant oils be modified to produce?

Answer 56

Biodiesel

Question 57

Name 2 advantages of biofuels

Answer 57

1. Produce **less greenhouse gases** (e.g. carbon dioxide) than fossil fuels when combusted 2. **Renewable**