Download Energy Conversion and Rural Electrification

Chapter 1
Introductions
Presentation Outline
 Basic terms and definitions
 Thermodynamic laws and principles
 Prime movers for energy conversion
 World energy trend
Definitions of Some Terms & Concepts
• Energy is the ability to do work and work is the
transfer of energy from one form to another.
• Energy comes in different forms - heat (thermal),
light (radiant), mechanical, electrical, chemical,
and nuclear energy.
• There are two types of energy - stored (potential)
energy and working (kinetic) energy.
• Potential Energy: is stored energy and the
energy of position (gravitational).
• Chemical Energy: is the energy stored in the
bonds of atoms and molecules.
• Biomass, petroleum, natural gas, propane and
coal are examples of stored chemical energy.
Introduction …
• Nuclear Energy: is the energy stored in the nucleus of an
atom- the energy that holds the nucleus together. The
nucleus of a uranium atom is an example of nuclear
energy.
• Stored Mechanical Energy: is energy stored in objects
by the application of a force. Compressed springs and
stretched rubber bands are examples of stored mechanical
energy.
• Gravitational Energy: is the energy of place or position.
Water in a reservoir behind a hydropower dam is an
example of gravitational energy. When the water is
released to spin the turbines, it becomes motion energy.
• Kinetic Energy: Kinetic energy is energy in motion- the
motion of waves, electrons, atoms, molecules and
substances. It exists in various forms.
• Radiant Energy: Radiant energy is electromagnetic
energy that travels in transverse waves. Radiant energy
includes visible light, x-rays, gamma rays and radio waves.
Solar energy is an example of radiant energy.
Introduction …
• Thermal Energy: Thermal energy (or heat) is the internal energy
in substances- the vibration and movement of atoms and
molecules within substances. Geothermal energy is an example of
thermal energy.
• Electrical Energy: Electrical energy is the movement of
electrons. Lightning and electricity are examples of electrical
energy.
• Electrical energy is more suitable form of energy.
– It can be transformed from one to another more
easily
– It can be transported long distance
– It can be easily stored for later use.
Types of Energy Resources
• Conventional Energy Source: a source of energy that has
been widely used for many years.
• Thermal-electric power plants, hydro-electric power plants, and
nuclear power plants are examples.
• Renewable Energy Resource: a source of energy that can be
used indefinitely, without running out.
• Wind, solar power , geothermal power are examples.
• Non-Renewable Energy Resource: a source of energy that is
in limited supply and could eventually be completely used up.
Examples: fossil fuels, nuclear power
• Energy Conversion: Concerned with the transformation of
energy from sources such as fossil fuel and radiation from Sun
into conveniently used forms such as electrical energy,
propulsive energy, heating and cooling.
Thermodynamics ….
• Thermodynamics: a science that deals with the
relations between heat and other forms of energy (such
as mechanical, electrical, or chemical energy), and, by
extension, of the relationships between all forms of
energy.
• For efficient conversion of energy from one form to
another, knowledge of thermodynamic laws and
principles is necessary
• Combined heat and power (CHP) is one example in
which thermodynamic laws are used. In CHP, the
waste heat from room heaters can be used to
generate power by using steam turbines.
Laws of Thermodynamics
• The Zeroth Law of Thermodynamics: If two systems are in
thermal equilibrium with a third, then they are in thermal
equilibrium with each other. This law is the basis of temperature
measurement.
• First Law of Thermodynamics:
The change in internal
energy of a closed system is equals to the heat added to the
system (or absorbed from the environment) minus the work
done by the system (or on the environment). This law is a
consequence of conservation of energy.
• Second Law of Thermodynamics It is impossible to extract an
amount of heat QH from a hot reservoir and use it all to do work
W. Some amount of heat QC must be exhausted to a cold reservoir.
World energy trend and challenges
Growth in wind
Renewable energy alternatives