efficiency + energy types

5 renewable energy sources

• wind

• solar

• hep

• tidal

• geothermal

Main 2 non-renewable fuels

• fossil fuels

• nuclear

Which energy source is mainly used for heating homes in the UK? What is mainly used to power vehicles?

h: natural gas

v: types of crude oil, diesel, petrol

What is sometimes mixed with petrol to make it more environmentally friendly?

biofuel

What actually is a fossil fuel?

hydrocarbon-containing material from remains of dead plants and animals

2 advantages of fossil fuels

• cheap

• don’t depend on conditions and environment at all

3 disadvantages of fossil fuels

• non renewable

• produce co2 which contributes to global warming

• toxic gases when burned e.g carbon monoxide, sulfur dioxide

How is nuclear energy made?

nuclear reactions e.g fission in nuclear power stations

3 advantages of nuclear power

• do not produce any pollutants

• does not depend on conditions or environment

• unlikely to run out for a very long time

3 disadvantages of nuclear power

• harmful radioactive waste so must be stored carefully

• expensive

• non renewable

How is wind power generated?

• blades on wind turbine spin due to wind

• spinning turns a generator which generates electricity

3 advantages that wind and solar have in common

• renewable

• cheap once they have been set up

• don’t produce any pollutants

2 disadvantages that wind and solar have in common

• dependant on conditions

• expensive to set up

Where does geothermal energy originate from?

• original formation of the planet

• radioactive decay of materials deep inside earth

Outline how geothermal power stations work

• happens in regions with high volcanic activity so ground is very hot

• cold water pumped so heated by hot rocks

• heated water can be used to heat our homes

• or turned into steam to turn turbines and therefore generators

3 advantages of geothermal energy

• cheap once set up

• renewable

• can be used to generate electricity or hot water

2 disadvantages of geothermal power

• only use in specific locations

• expensive to set up

How is biofuel different to a fossil fuel such as petrol?

b: made of living or recently dead organisms

f: made of organisms that died millions of years ago

3 advantages of biofuel

• renewable

• easy to transport

• can be used in the vehicles we have today

2 disadvantages of biofuel

• require large amount of land to grow

• require a lot of energy to harvest and process

Why is biofuel carbon neutral in theory but not in practice?

t: absorb same amount of co2 when they grow as when they are burned

p: cut down trees to make space, uses co2 to transport the biofuel

How is hep produced (3)

• water runs downhill, hep dam traps it

• spins turbine which spins generator

• water can then return to river downstream

How do tidal barrages generate electricity?

• as tide comes in dam traps water

• when tide comes back out water is released which spins turbines connected to generators

• water can then return to river downstream

2 advantages and disadvantages of hep

a: renewable, cheap once set up

d: expensive to set up, can disrupt natural habitats

What is wave power?

sea water rises and falls due to waves, so wave machine use this kinetic to turn turbines connected to generators

2 advantages and disadvantages of wave power

a: renewable, cheap

d: difficult to produce a lot of electricity, can affect wildlife