P3

Question 1

What is a biofuels?

Answer 1

A biofuel is any fuel taken from living or recently living organisms. Animal waste is an example of a biofuel.

Question 2

What can biofuel be used for?

Answer 2

Biofuel can be used instead of fossil fuel in modified engines for transport and in generators at power stations.

Question 3

Where does most the energy we use come from?

Answer 3

Most of the energy you use comes from burning fossil fuels, most,
oil or coal.

Question 4

Pros of biofuels

Answer 4

Biofuels are renewable and are carbon neutral.

Question 5

What is a renewable energy source?

Answer 5

It is an energy source that is either regrown or continually reproduced so it is used at the same rate it is replaced.

Question 6

What is a carbon-neutral energy source?

Answer 6

A carbon-neutral energy source is an energy source that releases the same amount of carbon that the living organisms take in to balance the amount that is released.

Question 7

What is nuclear energy?

Answer 7

Nuclear energy is a fuel that takes energy from atoms.

Question 8

How is nuclear energy made?

Answer 8

The fuel in a nuclear power station is uranium (or plutonium). The
uranium fuel is in sealed cans in the core of the reactor. The nucleus of a uranium atom is unstable and can split in two. Energy is transferred from the nucleus when this happens. Because there are lots of uranium atoms in the core, it becomes very hot. The energy of the core is transferred by a fluid (called the coolant) that is pumped through the core. The coolant is very hot when it leaves the core. It flows through a pipe to a heat exchanger, then back to the reactor core. The energy transferred by the coolant is used to turn water into
steam in the heat exchanger. The steam drives turbines that turn
electricity generators.

Question 9

What is wind power?

Answer 9

Wind power is energy generated by a wind turbine.

Question 10

How is wind power made?

Answer 10

A wind turbine is an electricity generator at the top of a narrow tower. The force of the wind drives the turbine’s blades around. This turns a generator. The power generated increases as the wind speed increases. Wind turbines are unreliable because when there is little or no wind they do not generate any electricity.

Question 11

What is wave power?

Answer 11

Wave power is energy made by a wave generator.

Question 12

How is wave power generated?

Answer 12

A wave generator uses the waves to make a floating generator move up
and down. This motion turns the generator so it generates electricity. A cable between the generator and the shoreline delivers electricity to the grid system.

Question 13

What is hydroelectric power?

Answer 13

Hydroelectric power is power that is power thats generated when rainwater is collected in a reservoir.

Question 14

How is hydroelectric power generated?

Answer 14

Hydroelectricity can be generated when rainwater that’s collected
in a reservoir (or water in a pumped storage scheme) flows downhill. The flowing water drives turbines that turn electricity generators at the bottom of the hill.

Question 15

How is tidal power made?

Answer 15

A tidal power station traps water from each high tide behind a barrage.
The high tide can then be released into the sea through turbines. The
turbines drive generators in the barrage.

Question 16

How is solar power made?

Answer 16

A solar heating panel heats water that flows through it. On a sunny day in Britain, a solar heating panel on a house roof can supply plenty of hot water for domestic use. A solar power tower uses thousands of flat mirrors to reflect sunlight on
to a big water tank at the top of a tower. The mirrors on the
ground surround the base of the tower. The water in the tank is turned to steam by the heating effect of the
solar radiation directed at the water tank.
The steam is piped down to ground level, where it turns electricity
generators. The mirrors are controlled by a computer so that they track the Sun. A solar power tower in a hot dry climate can generate more than 20 MW of electrical power, which is enough to power a few thousand homes.

Question 17

How is geothermal energy made?

Answer 17

Geothermal energy comes from energy released by radioactive
substances deep within the Earth.
The energy transferred from these radioactive substances heats the
surrounding rock. So energy is transferred by heating towards the Earth’s surface.

Question 18

What are some problems with fossil fuels?

Answer 18

When coal, oil, or gas is burnt, greenhouse gases such as carbon dioxide are released. The amount of these gases in the atmosphere is increasing, and most scientists believe that this is causing more global warming and climate change.

Question 19

Nuclear power advantages

Answer 19

No greenhouse gases (unlike fossil fuel). Much more energy is transferred from each kilogram of uranium (or plutonium) fuel than from fossil fuel.

Question 20

Nuclear power disadvantages

Answer 20

Used fuel rods contain radioactive waste which has to be stored
safely for centuries.

Nuclear reactors are safe in normal operation. However, an explosion in a reactor could release radioactive material over a wide area. This would affect this area, and the people living there, for many years.

Question 21

Renewable energy advantages

Answer 21

They will never run out because they are always being replenished by natural processes.

They do not produce greenhouse gases or acid rain.

They do not create radioactive waste products.

Question 22

Renewable power disadvantages

Answer 22

Renewable energy resources are not currently able to meet the world demand. So fossil fuels are still needed to provide some of the energy demand.

Wind turbines create a whining noise that can upset people nearby,
and some people consider them unsightly.

Tidal barrages affect river estuaries and the habitats of creatures and
plants there.