Prof vilas shamrao patil

1. RENEWABLE ENERGY RESOURCES
SYLLABUS:
Energy, Classification of energy resources, Age of
renewable and alternatives, Energy demands, Wind
energy, Wind energy chains, Wind energy quantum, Wind
power density, Power of a wind turbine for a given
incoming wind velocity, Efficiency factor of wind turbine
(P-H graph), Types of wind turbine generator unit,
Horizontal axis propeller type wind turbine generator unit.
1.1 INTRODUCTION:
The word energy has become a current coin of
everyone's day to day life. We talk of conventional and
non-conventional sources of energy, we talk of electrical
energy, light energy, heat energy, sound energy, nuclear
energy, chemical energy, solar energy, wind energy, food
energy (calories). We talk of energy crisis and complain
of energy (power) shortage. We are also aware of the
hazards of the pollution and danger to the environment
and ecology due to the various artificial energy generators.
But many a times we do not know the basic things about
energy and hence cannot properly link the interconnection
of all the things mentioned above. We are going to learn
about the basic things, their inter-relationship with the
scientific principles underlying them.
There is very dismal picture of energy scenario after
energy crisis of 1973. The demand is always exceeding the
supply. Most of the production of electricity is based on
conventional sources and their reserves are very limited -

2. likely to be depleted in next few decades. This forces the
researcher to go for non-conventional energy sources of
renewable type. As renewable energy resources are
replenished, they have very good prospects as an
alternative to conventional sources. In decades to come, the
world has to go for more and more use of renewable energy
sources with development in technology, increase in
efficiency, decrease in cost, increase in production of
conversion units and safe and pollution free energy.
Renewable energy sources are solar energy, wind energy,
biomass energy, ocean energy etc. In this chapter we deal
with some basic things related to energy - its types,
alternative source and demand of energy. This chapter also
deals with the wind energy, which has very good future as
renewable energy after solar energy.
1.2 ENERGY :
We have learnt in the high school level Physics that
energy is the capacity to do work. Every body in the
universe possesses some energy i.e. possesses the capacity
to do work. It is due to this that they do some activity in
some form of 'motion'. Thus, energy is the cause behind
the motion of bodies and is capable of producing motion,
force, work, change in shape, change in form etc. Part of
the energy used, when a body moves is called work.
We look at energy from different angles :
(1 ) Forms of energy
(2) Production of energy and
(3Actual use of energy.

3. 1. Forms of energy : Energy exists in many forms such as
chemical energy (Ech), nuclear energy (Enu), solar energy
(Eso), mechanical energy (Eme), electrical energy (Eec),
internal energy of a body (Ein), energy from vegetables and
animals i.e. bio-energy (Ebi), thermal energy (Eth).
But we know by the principle of conservation of energy
that the total energy in the universe is constant; energy
cannot be created or destroyed; its form can be changed.
Therefore, all forms of energy (mentioned above) are
interconvertible as they are the manifestations of same
energy.
2. Production of energy : Production of energy means
converting one
form of energy into another convenient form depending
upon the use aimed at. For example, electric power
(energy) is used in generating heat. For this conversion
technology has to be used. The conversion consists of
three things :
(a) Primary energy or raw matter : It contains the
resources of energy. like coal, fissile nucleus, petrollum,
present in the nature. .
(b) Intermediate energy : It is obtained from primal
resources by some process or processes. For example;
nuclear energy is obtained as an enormous heat energy by
fission reaction.
(c) Secondary or Usable energy : This is the suitable form
of energy for the consumer for final consumption. For

4. example, the electrical energy supplied to the consumer
obtained from the nuclear (heat) energy.
Thus, the chain is : Primary energy-Intermediate energy
Secondary (Usable)-energy.
The intermediate energy can be divided into two parts :
(1) Useful energy : It is the energy from the resource
which can be actually put to use and Worthless energy : It
is that part of the energy which cannot be transformed into
usable energy. For example If coal is burnt, only 40% of it
gives heat energy; so useful energy is only 40%. (2)
worthless Energy:- The rest 60% is worthless. The
technology such aims at obtaining maximum useful
energy by minimizing losses. i.e. yield (output) percentage
should be maximum.
3. Actual use (useful) energy : It may consist of
transportation. This has a direct concern with the actual
use, efficiency of the tool used for consumption etc. But it
should be noted that some primary energy can be directly
used for secondary or usable energy. e.g, fire wood can be
directly used as a fuel; solar heat can be directly used for
heating water or cooking.
Man and Environment- Man is the only animal who
uses all forms and all types of sources of energy. But the
resources of 'primary energy which can be directly used as
usable energy are very few and costly too. Therefore, man
has developed technology of various kinds to transform
primary resources into intermediate ones and then into
usable energy. Many techniques have been invented in the

5. fields of agriculture, clothing, erection of building, big
dams for hydroelectric power, medicine, cars, aeroplanes,
rockets, communication by telephone, mobile, petroleum
products, nuclear energy, luxuries like cosmetics, air
coolers, refrigerators and many others. A major portion of
the energy is transformed to electrical form by power
plants (based on using hydro power, thermal power,
nuclear power etc.)
But for the conversion of primary resources into
intermediate and finally into usable energy coal has to be
burnt, coal mines have to be dug, woods have to be cut,
chemicals have to be burnt, on a very big scale. Here then,
comes the problem of tampering with the ecobalance and
pollute the environment to hazardous effect. Chemical
industries pour enormous amounts of solid particles, harmful
gases like SOx, NOx, CO, CO2 chemical waste polluting
rivers, lakes and endangering animal and plant life. Due to
CO2, the greenhouse effect is required to be paid attention
to. The layer of ozone in the atmosphere protecting the
earth from the harmful ultraviolet rays is broken; the
temperature of the atmosphere is rising (Global warming).
All these things are spoiling the ecobalance, and
environment creating fatal danger to the animal and plant
kingdom in general and human race in particular.
And the degree or level of the danger is increasing year
by year because the world's human population is growing
and thereby world's annual consumption rate of energy is
increasing by 2 to 4 per cent.

6. Fig. (1.1) shows the close relationship between the
human life and energy, energy conversion processes and
environment.
If the ecobalance, en- vironment are to be properly
maintained to save the life on the earth, stringent measures
have to be taken and new methods have to be developed to
minimise existing
Fig.1.1 : Close relationship between Energy, pollution
(like developing
Environment and Conversion processes renewable
energy technologies, retrofitting existing plants by adding
electrostatic precipitants, chemical treatment plants etc.)
and to take care to have antipollution techniques built up
with new plants and industries.
Energy is cause behind the motion of body. It is the
capability to produce motion. From physics point of view,
energy is nothing but the capacity of body or a particle to
do work (W). The work is dot product of force and

7. displacement. Hence, energy is the sole cause behind
formation of force and displacement i.e. motion. From
thermodynamical .considerations energy has two forms —
(i) Exergy is that part of energy which gives useful work
and
(ii) Anergy is worthless energy not useful for doing work.
The exergy available from 1 gram of uranium, 1 gram of
coal, 1 gram of petrol, solar energy on unit area, wind
energy on unit area, etc. are not equal. From law of
conservation of energy, the energy can neither be created
nor destroyed. It can be converted from one form to the
other. Therefore, production of energy is nothing but
transformation of energy of one form into the other. No
new energy can be produced. It is found that solar energy
is origin of all other energies. Energy is available in
different forms. These are kinetic (mechanical) energy,
potential energy, nuclear energy, biomass, solar, wind,
ocean, chemical energy, etc. Use of energy is necessary
almost from home appliances to industry, space and from
food to cosmetics. This increased the consumption on large
scale.
Further, the energy can be used in direct or indirect way.
Percentage contribution of various energy sources to the
total electricity production of the world is given in Table
1.1.

8. This table shows that most of the energy sources used for
electricity production is conventional. After 2005 the
percentage contribution of other non-conventional sources
has increased.