Energy

S6E6.a Explain the role of the sun as the major source of energy and the sun’s relationship to wind and water energy.

S6E6.b Identify renewable and nonrenewable resources

What is energy?

• Energy is the ability to do work.

Why is energy important?

• We use energy to do everything we do. – Thinking– Playing – Working– Cooking– You name it!

What is the ultimate source of all energy on Earth?

• The Sun!– The sun’s energy

powers all other energy sources.

– The sun’s energy powers wind and waves.

– Plants convert the sun’s energy into fuel we can use through photosynthesis.

What are the two types of energy?

• Potential Energy– Stored energy

• Kinetic Energy– Energy of motion

In what forms are potential energy and kinetic energy found?

• Heat or thermal energy

• Light (radiant)• Mechanical/kinetic • Electrical, • Chemical, • Nuclear energy

How are these forms of energy stored?

• Renewable resources– an energy source that can be

replenished in a short period of time

• Nonrenewable resources– an energy source that we are

using up and cannot recreate in a short period of time

Secondary Energy Sources

• An energy source (or carrier) derived from the conversion of other sources of energy, such as coal, nuclear, or solar energy. These are called primary sources.

• Electricity• Hydrogen

How is energy used in homes?

• Most energy in homes is used for heating.

What are the sources of renewable energy?

What are the pros (good things) about using these resources?

What are the cons (bad things) about using these resources?

Solar EnergyEnergy from the Sun

• Solar energy is the sun’s rays (solar radiation) that reach the earth.

• Solar energy can be converted into other forms of energy, such as heat and electricity.

Solar Energy• Solar energy can be converted to thermal

(or heat) energy and used to:

• Heat water – for use in homes, buildings, or swimming pools.

• Heat spaces – inside greenhouses, homes, and other buildings.

Solar Power Advantages

• Solar energy is free• Its supplies are unlimited. • Using solar energy

produces no air, sound, or water pollution

• Low maintenance on equipment because no moving parts

• Photovoltaic cells can be used on a variety of products (The little panel on your calculator)

Solar PowerDisadvantages

• The initial investment in equipment can be very expensive

• Solar power plants require a lot of room and can affect environment in areas where they exist

• Requires sunlight so it is not produced 24 hours a day

• Requires expensive batteries to store energy for use on cloudy days and at night