Energy is the ability to do work. The word
‘work’ means transferring energy from one place
to another. energy is neither destroyed nor
created. It can only be changed.
Types of
Any object in motion has
mechanical energy. For
example a ball flying
through the air.
Energy caused by
the movement of
Easily transported
through power lines
and converted into
other forms of energy.
• Comes from bonds between
atoms in molecules
• Chemical change = energy
• Examples:
•Gasoline burning in a car
•Food we eat
Comes from reactions
between atomic nuclei.
Fission splits
Fusion combines
HUGE amounts of
 Includes
from gamma rays, xrays, ultraviolet rays,
visible light, infrared
rays, microwave and
radio bands.
The Thermal energy is
the internal kinetic
energy and it considers
the motion of every
constitutive particle of
the system (molecules,
atoms, electrons, etc.).
•Vibration of molecules
in surrounding medium
(usually air).
Flows through empty space
Radio waves
Renewable Energy
Those sources of energy which are being produced
continuously in nature and will never be
exhausted, are called renewable sources of
Non-renewable Energy
Those sources of energy which have been produced
in nature over a very, very long time and cannot be
quickly replaced when exhausted, are called non
renewable sources of energy.
Renewable sources Energy
Solar energy
Solar energy is the most readily
available source of energy. It
does not belong to anybody and
is, therefore, free. It is also the
most important of the nonconventional sources of energy
because it is non-polluting and,
therefore, helps in lessening the
greenhouse effect.
Biomass is a renewable energy resource derived from
the carbonaceous waste of various human and natural
activities. It is derived from numerous sources,
including the by-products from the timber industry,
agricultural crops, raw material from the forest, major
Hydel Energy
The energy in the flowing water can be used to
produce electricity. Waves result from the interaction
of the wind with the surface of the sea and represent
a transfer of energy from the wind to the sea. Energy
can be extracted from tides by creating a reservoir or
basin behind a barrage and then passing tidal waters
through turbines in the barrage to generate electricity.
Geothermal Energy
We live between two great
sources of energy, the hot
rocks beneath the surface of
the earth and the sun in the
sky. Our ancestors knew the
value of geothermal energy;
they bathed and cooked in hot
springs. Today we have
recognized that this resource
has potential for much broader
Wind Energy
Wind energy is the kinetic energy
associated with the movement of
atmospheric air. It has been used for
hundreds of years for sailing, grinding
grain, and for irrigation. Wind energy
systems convert this kinetic energy to
more useful forms of power. Wind
energy systems for irrigation and
milling have been in use since ancient
times and since the beginning of the
20th century it is being used to
generate electric power. Windmills for
water pumping have been installed in
many countries particularly in the
Non- Renewable Energy
Coal is the most abundant
fossil fuel in the world.
During the formation of
coal, carbonaceous matter
was first compressed into a
spongy material called
"peat," which is about 90%
water. As the peat became
more deeply buried, the
increased pressure and
temperature turned it into
Crude oil or liquid petroleum,
is a fossil fuel that is refined
into many different energy
products (e.g., gasoline, diesel
fuel, jet fuel, heating oil). Oil
forms underground in rock
such as shale, which is rich in
organic materials.
Nuclear power
In most electric power plants,
water is heated and converted
into steam, which drives a
turbine-generator to produce
electricity. Fossil-fueled power
plants produce heat by burning
coal, oil, or natural gas. In a
nuclear power plant, the fission
of uranium atoms in the reactor
provides the heat to produce
steam for generating electricity.
Natural gas
Natural gas production is often a byproduct of oil recovery, as the two
commonly share underground reservoirs.
Natural gas is a mixture of gases, the
most common being methane (CH4). It
also contains some ethane (C2H6),
propane (C3H8), and butane (C4H10).
Natural gas is usually not contaminated
with sulfur and is therefore the cleanest
burning fossil fuel.