What is energy? ▪The ability to do work or cause change and the capacity for vigorous activity.
▪Work is the application of a force through a distance. Force can put matter into motion or
stop it if it is already moving.
▪ Motion is a change in position of an object with time. To do work, energy is needed.
From where does energy come?
▪Power plants, people, food, light, windmills, turbines, fires, etc.
Life as we know it would not be possible without energy production and consumption.
❑Energy Conversion is when energy changes from one form to another. When energy moves
from one place to another it is known as energy transfer.
❑How do we use energy?
▪Our bodies use energy to break down and digest food.
▪Cells use energy to perform the most basic life functions.
▪Inside the sun, nuclear energy in atoms is converted into heat energy, making the surface ferociously
▪DID YOU KNOW! Sound energy is used in communication and to find fish in the ocean!
❖Can you name a form of energy?
The answer is Energy exists in many different forms. Examples: Light, heat,
electricity, sound.
❑POTENTIAL ENERGY is energy that is stored up within a body or system
ready for action.
❑KINETIC ENERGY is energy that is possessed by an object because it is
moving. A rolling ball has kinetic energy.
➢What are different types of energy?
Chemical, Thermal, Mechanical, Potential, Kinetic, Solar, Sound, Nuclear, etc.
WHEN fuels such as gas are burned, chemical energy is changed into heat energy.

Energy Conservation
❖IN PHYSICS THE ENERGY CONSERVATION is the effort made to reduce the consumption of energy
by using less of an energy service.
❖OR the principle by which the total energy remains constant in a system that is not subject to
external influence.
❖ This can be achieved either by using energy more efficiently or by reducing the amount of
service used.
❖Energy conservation is a part of the concept of Eco-sufficiency.
Energy conservation measures (ECMs) reduce the need for energy and can result in increased
environmental quality, national security, personal financial security and higher savings.
Non-Renewable Energy
Renewable Energy
Natural gas Wind
Coal Water
Oil Solar
Other Fossil Fuels Biomass
❖ Non-renewable sources of energy as those
sources that once used up cannot regenerate
❖ Renewable sources of energy are those
sources, which can regenerate themselves time
and again thus making them an infinite source
of energy.
What percent of the energy the world uses today is
derived from fossil fuels (e.g., coal, oil, natural gas)?
❖80-85% of the energy the world
uses today is derived from fossil
❖This means that only 15-20% of the
energy we use is from renewable
energy sources such as sun, wind
and water.
➢Imagine what today would be like if there were no electricity (permanently, not just a
blackout situation).
➢From where do you think we get the power/or the electricity?
➢Energy takes many forms!
❖Using clean, renewable energy is one of the most important actions you can take to
reduce your impact on the environment.
❖It is possible to make electricity from renewable energy sources without producing
carbon dioxide (CO2), the leading cause of global climate change.
❖Renewables Benefit the Economy:
I. Energy Security,
II. Economic Development,
III. Price Stability.
The five sources of renewable energy.
❖Energy can neither be created nor destroyed but it can
be transformed from one form to another. This is known as
the Law of conservation of energy.
❖Renewable energy is any type of energy that can be
renewed in a short amount of time, or is being continually
replenished or regenerated.
❖These types of energy are not used as fast as they are
❖ Renewable energy sources include solar, wind,
geothermal, biomass, ocean and hydro (water).
Have you ever felt a strong wind?
What could you do with a steady, strong wind? sail a boat, dry laundry on a
line, turn a windmill, open the window to cool or air out your house, etc.
When we get wind to do something for us, we are making it work.
Who remembers the definition of energy? Energy is when something does work.
Using this definition, wind is an energy!
❖Wind power energy is a renewable energy
source and it does not pollute the environment.
❖A wind turbine converts the kinetic (movement)
energy of the wind into electric energy.
❑What is a wind turbine? A machine that converts
the moving energy of wind into mechanical energy.
❑What is a wind farm? A power plant composed of
many wind turbines that create electricity.
❑What happens when there is no wind? No work
can be done. So, it is important to be able to store
the wind energy for continual use.