UNIT 1 PHYSICS - RENEWABLE ENERGY RESOURCES 1

FEB EXAM

What is a renewable energy source?

A renewable energy source is one that will never run out.

It can be used again and again, unlike non-renewable such as coal or oil.

Examples:

• Hydroelectricity

• Wave power

• Tidal power

• Solar power

• Geothermal energy

• Biofuels

What is hydroelectricity?

Hydroelectricity uses water stored behind a dam to generate electrical energy.

The dam collects and stores rainwater in a reservoir.

How does hydroelectric power work?

1. Water stored behind the dam has gravitational potential energy.

2. When released, the water falls, turning turbines - this gives it kinetic energy.

3. The turbines turn a generator, which transforms kinetic energy into electrical energy.

What are the energy transfers in hydroelectricity?

Gravitational potential energy (of stored water)

→ Kinetic energy (as it falls and moves)

→ Electrical energy (produced by the generator)

What are the advantages and disadvantages of hydroelectricity?

Advantages:

• Electricity can be made whenever it’s needed

• Renewable and clean source of energy

Disadvantages:

• Building a dam is very expensive

• Villages and habitats may be flooded to create reservoirs.

What is wave power?

Wave power uses up and down movement of waves to turn a turbine.

The moving air caused by the winds spins the turbine, which drives a generator to produce electricity.

What are the energy transfers in wave power?

Kinetic energy (of waves)

→ Electrical energy

• The kinetic energy of the waves forces air to turn a turbine and generator

• The generator transforms this kinetic energy into electrical energy.

What are the advantages and disadvantages of wave power?

Advantages:

• Useful on small islands

Disadvantages:

• Unreliable (depends on wind strength)

• Doesn’t give much energy

What is tidal power?

Tidal power uses tidal barrages - big dams built across rivers or estuaries.

As the tide flows in and out, it turns turbines, which drive generators to produce electricity.

What are the energy transfers in tidal power?

Kinetic energy (of moving water)

→ Electrical energy

• The moving water turns the turbine

• The generator transforms the kinetic energy into electrical energy

What are the advantages and disadvantages of tidal power?

Advantages:

• Gives loads of energy

• Very reliable (tides happen every day)

Disadvantages:

• Can only be used in certain places