8.2. Sources of energy

1. NON-RENEWABLE

Non-renewable energy comes from sources that will run out or will not be replenished in our lifetimes—or even in many, many lifetimes. Most non-renewable energy sources are fossil fuels: coal, petroleum, and natural gas.

Nonrenewable resources are those found inside the earth, and they took millions of years to form. Today, close to 84% of the total amount of energy used globally comes from fossil fuels.

Advantages and Disadvantages

Fossil fuels are a valuable source of energy. They are relatively inexpensive to extract. They can also be stored, piped, or shipped anywhere in the world.

However, burning fossil fuels is harmful for the environment. When coal and oil are burned, they release particles that can pollute the air, water, and land. Some of these particles are caught and set aside, but many of them are released into the air.

2. RENEWABLE ENERGY SOURCES

Renewable energy is energy that is collected from renewable resources, which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat.

Renewable Energy Project

EXPERIMENTS

8.1. Forms of energy

Forms of energy:

• Many forms of energy exist, but they all fall into two basic categories:
• - Potential energy
• - Kinetic energy

UNIT 8: ENERGY

WHAT ARE WE GOING TO LEARN?
- What energy is
- Forms of energy
- Energy sources: renewable and non-renewable
- Electricity and magnetism

WHAT IS ENERGY?

DEFINITION: Energy is the ability to do work.

People use energy for everything from making a jump shot to sending astronauts into space. There are two types of energy:

1. Stored (potential) energy

1. Working (kinetic) energy

For example, the food a person eats contains chemical energy, and a person's body stores this energy until he or she uses it as kinetic energy during work or play.