UNIT 1 PHYSICS - RENEWABLE RESOURCES 2

FEB EXAM

What is wind power?

Wind turbines use the kinetic energy of moving air (wind) to produce electrical energy.

The blades of the turbine spin when the wind blows.

How does wind power work?

1. The wind has kinetic energy that turns the blades of a wind turbine.

2. The blades turn a generator, which transforms kinetic energy into electrical energy.

What is the energy transfer in wind power?

Kinetic energy (of wind)

→ Electrical energy

What are the advantages and disadvantages of wind power?

Advantages:

• Can be used on a small or large scale

• Useful in remote places (without mains electricity)

Disadvantages:

• Only works when it’s windy

What are solar cells?

Solar cells transform light energy from the Sun into electrical energy.

A solar panel is made up of many solar cells

What is the energy transfer in solar cells?

Light energy (from the Sun)

→ Electrical energy

What are the advantages and disadvantages of solar cells?

Advantages:

• Reliable in sunny places during the daytime

• Can be used on a small or large scale

• Useful in remote places

Disadvantages:

• Don’t work at night or when it’s cloudy

What is geothermal energy?

It’s heat from underground - produced by hot rocks beneath the Earth’s surface

How does geothermal energy work?

1. Water is pumped down to hot rocks underground.

2. It comes back up as steam

3. The steam drives a turbine, which powers a generator to produce electricity

What are the energy transfers in geothermal power?

Heat energy (from hot rocks) → Kinetic energy (steam turns turbine) → Electrical energy (from generator)

What are the advantages of geothermal energy?

• Cheap to run

• Renewable

• Produces little pollution

What are the disadvantages of geothermal energy?

• Can only be used where hot rocks are near the surface

• Not many locations suitable for it

What are biofuels?

Biofuels are made from plants and used as an energy source

How are biofuels used to generate electricity?

1. Biofuels are burnt to heat water

2. The steam drives a turbine

3. The turbine turns a generator, producing electricity

What are the energy transfer in biofuel power?

Chemical energy (in biofuel) → Heat energy (when burnt) → Kinetic energy (of steam turning turbine) → Electrical energy (from generator)

What are the advantages of biofuels?

• Quick and cheap to make

• Renewable (plants can be regrown)

What are the disadvantages of biofuels?

• Need lots of land to grow crops for fuel

• Can affect food supply or deforestation