Research Internship Report

A
Project Report
On
Energy Conservation Techniques
At
Gujarat Urja Vikas Nigam Limited
Submitted in the partial fulfilment of the Award of Degree of
Bachelor of Technology
In
Electrical Engineering
From Gujarat Technological University, Gujarat
May-2013
Guided By:
___________ ____________
(Internal Guide) (External Guide)
Mr. Tapan Kakadia Mr. Y. D. Bhrahbhatt
Assistant Professor Chief Engineer
Engineering College, Tuwa. GUVNL- Vadodara
Submitted By:
Arpit Suthar K. (100553109006)

2
ACKNOWLEDGEMENT
We would like to thank Dr. Bharat B. Mistry, Principal, Engineering
College Tuwa specially, to permit us to opt for Industry defined project.
We take immense pleasure in thanking Mr. Y. D. Bhrahbhatt, Chief
Engineer, GUVNL for having permitted us to carry out this project work.
We wish to express our deep sense of gratitude to our Internal Guide, Mr.
Tapan Kakadia, Asst. Prof., Engineering College Tuwa for his able
guidance and useful suggestions, which helped us in completing the project
work, in time.
Special Thanks to Mr. M. R. Patel, GUVNL who has been a source of
inspiration and for his timely guidance in the conduct of our project work at
the Industry. We would also like to thank Mr.Harendra Pushpat (HOD)
Engineering College Tuwa for all his valuable support in the project work.
Also thanking to Words are inadequate in offering our thanks to the Project
Guides for their encouragement and cooperation in carrying out the project
work.
Finally, yet importantly, we would like to express our heartfelt thanks to our
beloved parents for their blessings, our friends/classmates for their help and
wishes for the successful completion of this project.
Suthar Arpit K. (100553109006)
7th Semester Electrical Engineering
Engineering College Tuwa

3
ABSTRACT
“ENRGY SAVER FOR INDUSTRIAL AND COMMERCIAL ESTABLISHMENT”
The project is designed to reduce the energy loss in industries by power factor compensation
through a number of shunt capacitors. This results in reduction in amount of electrical bill for
industries and commercial establishments. Power factor is defined as the ratio of real power
to apparent power. This definition is often mathematically represented as KW/KVA, where
the numerator is the active (real) power and the denominator is the (active + reactive) or
apparent power. Reactive power is the non working power generated by the magnetic and
inductive loads, to generate magnetic flux. The increase in reactive power increases the
apparent power, so the power factor also decreases. Having low power factor, the industry
needs more energy to meet its demand, so the efficiency decreases. In this proposed system
the time lag between the zero voltage pulse and zero current pulse duly generated by suitable
operational amplifier circuits in comparator mode are fed to two interrupt pins of the
microcontroller. Microcontroller displays the energy loss due to the inductive load on the
LCD. The program takes over to actuate appropriate number of relays at its output to bring
shunt capacitors into the load circuit to get zero energy loss. The 8 bit microcontroller used
in the project belongs to 8051 family. Further the project can be enhanced by using Thyristor
control switches instead of relay control to avoid contact pitting often encountered by
switching of capacitors due to high in rush current.
“ENERGY CONSERVATION IN POWER GENERATION”
To gain an appreciation for the impact that improved efficiency can have, it is useful to
examine the price we pay for inefficiency, and nowhere is this more apparent than in the
generation of electric power. Typically, the process converts the latent energy in a fuel stock
(coal, gas, uranium) into mechanical energy in a generator and ultimately electrical energy.
However, other generation sources like wind and hydro power use the mechanical energy of
moving masses of air or water to produce electric energy. Still other devices, such as fuel
cells, use chemical reactions to generate electric energy. In all of these cases, though, some
of the input energy is lost in the process. The efficiency of generation varies widely with the
technology used. In a traditional coal plant, for example, only about 30-35% of the energy
in the coal ends up as electricity on the other end of the generator. So called “supercritical”
coal plants can reach efficiency levels in the mid-40, and the latest coal technology, to
known as integrated gasification combined cycle or IGCC is capable of efficiency levels
above 60%. The most efficient gas-fired generators achieve a similar level of efficiency.
Obviously, though, even at 60% efficiency there is a tremendous amount of energy left
behind in the generation process. That represents a higher cost of production for the
generator, as well as a substantial waste of limited resources. There is, therefore, tremendous
economic and ecological incentive to improve the efficiency of power generation so that
more of the energy content of the input fuel is carried through to the output electricity. There
are a variety of ways to improve generator efficiency, such as combustion optimization using
modern control systems, but for the purposes of this paper we will focus on what happens
after the generation process.
Once electric energy is generated, it must be moved to areas where it will be used. This is
known as transmission—moving large amounts of power over sometimes very long
distances—and is separate from distribution, which refers to the process of delivering
electric energy from the high voltage transmission grid to specific locations such as a
residential street or commercial park.

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Engineering Collage Tuwa
Department of Electrical Engineering
CERTIFICATE
This is to certify that the project entitled “Energy Conservation Techniques” is being
submitted by Mr. Darji Ankur S. & Mr. Suthar Arpit K. for the partial fulfilment of the
award of the degree of Bachelor of Engineering (Electrical Engineering) from Gujarat
Technical University. He has completed this project successfully under my guidance and
full filled all requirements.
Date:
Project Guide Head of Department External Examiner

5
CONTENTS Page No
Chapter-1 Energy Saver for Industrial and Commercial Establishment 9
1.1 Power Factor Improvement 10
1.1.1 Alternating Current Circuits 10
1.1.2 Capacitor for Power factor Improvement 11
1.1.3 Location of Power Factor Improvement Capacitor Bank 12
1.1.4 Power Factor Correction 12
1.1.5 Power Factor in Linear Circuits 13
1.1.6 Definition and Calculation 13
1.1.7 Power Factor Correction of Linear Loads 14
1.1.8 Non-Linear Loads 15
1.1.9 Non-Sinusoidal Components 15
1.1.10 Distortion Power Factor 16
Chapter-2 Model Explanation 17
2.1 Block Diagram and Schematic Diagram 18
2.2 Description 20
2.2.1 Power Supply 20
2.2.2 Standard Connection to 8051 Series Microcontroller 20
2.2.3 Brief Description of Working of Relay 21
2.2.4 ULN 2003 Relay Driver IC 22
2.3 Operation Explanation 23
2.4 Circuit Explanation 25
2.5 Layout Diagram 27
2.6 Hardware Requirement 28
2.6.1 Hardware Components 28
2.7 Software Requirement 29
2.8 Coding 34
2.9 Estimation of Materials 48
Chapter-3 Energy Conservation in Power Generation 50
3.1 Energy Conservation According to Conventional Sources 51
3.2 Use of Cogeneration Plant 52
3.3 Types of Cogeneration System 53
3.3.1 Steam Turbine Cogeneration System 53
3.3.2 Gas Turbine Cogeneration System 54
3.3.3 Reciprocating Engine Cogeneration System 54
3.3.4 Option Checklist 55
3.4 Mini Hydro Power Plant 56
3.4.1 The Benefits of Mini Hydro Power System 60
3.4.2 Will Hydro Power Work for us? 61
3.4.3 Off Grid 61
3.4.4 Costs, Saving and Earning 62
Chapter-4 Innovation in Renewable Energy Sources 63
4.1 Energy Conservation According to Non-Conventional Sources 64
4.2 Megenn Air Rotor System (MARS) 64
4.2.1 Construction and Working 64
4.2.2 MARS Target Markets Include 67
4.2.3 Advantages of MARS over Conventional Wind Turbines 68

6
4.2.4 Conclusion 69
4.3 Osmotic Power-a new Renewable Energy Sources 70
4.3.1 The Power of Osmosis 71
4.3.2 Conclusion 73
References 74

7
LIST OF FIGURE
Figure
No.
Figure Name Page
No.
1 Waveforms for Inductive Load 10
2 Waveforms for Capacitive Load 11
3 Block Diagram 18
4 Schematic Diagram 19
5 Working of Relay 21
6 Relay Driver 22
7 Layout 27
8 Energy Efficiency Advantage of a Cogeneration 52
9 Hydropower Basics-Head & Flow 57
10 Hydro-Scheme Components 59
11 Hydropower Basics-Different Site Layouts 60
12 Working of MARS 65
13 End Plate With 5 kW Generator Attached to One Side 66
14 Pressure-Retarded Osmosis 71
15 Osmotic-Block Diagram 72

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LIST OF TABLE
Table
No.
Title of Table Page
No.
1 The Delay Time and Switch ON as Many Capacitors 26
2 Estimation of Materials 48
3 Typical Cogeneration Performance Parameter 55
3 Specification of MARS 69

9
CHAPTER: 1
ENERGY SAVER FOR INDUSTRIAL AND COMMERCIAL
ESTABLISHMENT

10
1.1 Power factor improvement:
1.1.1 Alternating current circuits:
Unlike Director Current Circuits, where only resistance restricts the current flow, in
Alternating Current Circuits, there are other circuits aspects which determines the current
flow; though these are akin to resistance, they do not consume power, but loads the system
with reactive currents; like D.C. circuits where the current multiplied by voltage gives watts,
here the same gives only VA.
Like resistance, these are called “Reactance”. Reactance is caused by either inductance or
by capacitance. The current drawn by inductance lags the voltage while the one by
capacitance leads the voltage. Almost all industrial loads are inductive in nature and hence
draw lagging wattles current, which unnecessarily load the system, performing no work.
Since the capacitive currents is leading in nature, loading the system with capacitors wipes
out them.
FIGURE 1: WAVEFORMS FOR INDUCTIVE LOAD

11
FIGURE 2: WAVEFORMS FOR CAPACITIVE LOAD
1.1.2 Capacitors for power-factor improvement:
Whatever the power factor is, however, the generating authority must install machines
capable of delivering a particular voltage and current even though, in a particular case, not
all the voltage and current products is being put to good use. The generators must be able to
withstand the rated voltage and current regardless of the power delivered. For example, if
an alternator is rated to deliver 1000A at 11000 volts, the machine coils must be capable of
carrying rated current. The apparent power of such a machine is 11 M V A and if the load
power factor is unit this 11 MVA will be delivered and used as 11 MW of active power i.e.
the alternator is being used to the best of its ability. If, however, the load power factor is say,
0.8 lagging, then only 8.8 MW are taken and provide revenue, even though the generator
still has to be rated at 1000A at 11 kV. The lower the power factor, the worse the situation
becomes from the supply authorities’ viewpoint. Accordingly, consumers are encouraged to
improve their load power factor and in many cases are penalized if they do not. Improving
the power factor means reducing the angle of lag between supply voltage and supply current.
1.1.3 Location of power-factor improvement capacitor banks:

12
Any installation including the following types of machinery or equipment is likely to have
low power factor which can be corrected, with a consequent saving in charges, by way of
reduced demand charges, lesser low power factor penalties:
1. Induction motors of all types (which from by far the greatest industrial load on a. c. mains).
2. Power thyristor installation (for D.C. motor control and electro-chemical processes).
3. Power transformers and voltage regulators.
4. Welding machines
5. Electric-arc and induction furnaces.
6. Choke coils and magnetic system.
7. Neon signs and fluorescent lighting.
Apart from penalties like maximum demand charges, penalty for low power factor, the
factory cabling and supply equipment can be relieved of a considerable wattles or reactive
load, which will enable additional machinery to be connected to the supply without enlarging
these services. Additionally, the voltage drop in the system is reduced.
The method employed to achieve the improvements outlined involves introducing reactive
kVA (kvar) into the system in phase opposition to the wattles or reactive current mentioned
above the effectively cancels its effect in the system. This is achieved either with rotary
machines (synchronous condensers)
1.1.4 Power Factor Correction:
The power factor of an AC electric power system is defined as the ratio of the real power
flowing to the load to the apparent power in the circuit, and is a dimensionless number
between 0 and 1 (frequently expressed as a percentage, e.g. 0.5 pf = 50% pf). Real power is
the capacity of the circuit for performing work in a particular time. Apparent power is the
product of the current and voltage of the circuit. Due to energy stored in the load and returned
to the source, or due to a non-linear load that distorts the wave shape of the current drawn
from the source, the apparent power will be greater than the real power.
In an electric power system, a load with a low power factor draws more current than a load
with a high power factor for the same amount of useful power transferred. The higher
currents increase the energy lost in the distribution system, and require larger wires and other
equipment. Because of the costs of larger equipment and wasted energy, electrical utilities
will usually charge a higher cost to industrial or commercial customers where there is a low
power factor.
Linear loads with low power factor (such as induction motors) can be corrected with a
passive network of capacitors or inductors. Non-linear loads, such as rectifiers, distort the
current drawn from the system. In such cases, active or passive power factor correction may

13
be used to counteract the distortion and raise the power factor. The devices for correction of
the power factor may be at a central substation, spread out over a distribution system, or
built into power-consuming equipment.
1.1.5 Power factor in linear circuits:
In a purely resistive AC circuit, voltage and current waveforms are in step (or in phase),
changing polarity at the same instant in each cycle. All the power entering the loads is
consumed. Where reactive loads are present, such as with capacitors or inductors, energy
storage in the loads result in a time difference between the current and voltage waveforms.
During each cycle of the AC voltage, extra energy, in addition to any energy consumed in
the load, is temporarily stored in the load in electric or magnetic fields, and then returned to
the power grid a fraction of a second later in the cycle. The "ebb and flow" of this non
productive power increases the current in the line. Thus, a circuit with a low power factor
will use higher currents to transfer a given quantity of real power than a circuit with a high
power factor. A linear load does not change the shape of the waveform of the current, but
may change the relative timing (phase) between voltage and current.
Circuits containing purely resistive heating elements (filament lamps, strip heaters, cooking
stoves, etc.) have a power factor of 1.0. Circuits containing inductive or capacitive elements
(electric motors, solenoid valves, lamp ballasts, and others) often have a power factor below
1.0.
1.1.6 Definition and calculation:
AC power flow has the three components: real power (also known as active power) (P),
measured in watts (W); apparent power (S), measured in volt-amperes (VA); and reactive
power (Q), measured in reactive volt-amperes
The power factor is defined as:
In the case of a perfectly sinusoidal waveform, P, Q and S can be expressed as vectors that
form a vector triangle such that:
If is the phase angle between the current and voltage, then the power factor is equal to the
cosine of the angle, and:
Since the units are consistent, the power factor is by definition a dimensionless number
between 0 and 1. When power factor is equal to 0, the energy flow is entirely reactive, and
stored energy in the load returns to the source on each cycle. When the power factor is 1, all
the energy supplied by the source is consumed by the load. Power factors are usually stated
as "leading" or "lagging" to show the sign of the phase angle.
If a purely resistive load is connected to a power supply, current and voltage will change
polarity in step, the power factor will be unity (1), and the electrical energy flows in a single
direction across the network in each cycle. Inductive loads such as transformers and motors
(any type of wound coil) consume reactive power with current waveform lagging the

14
voltage. Capacitive loads such as capacitor banks or buried cable generate reactive power
with current phase leading the voltage. Both types of loads will absorb energy during part
of the AC cycle, which is stored in the device's magnetic or electric field, only to return this
energy back to the source during the rest of the cycle.
For example, to get 1 kW of real power, if the power factor is unity, 1 kVA of apparent
power needs to be transferred (1 kW ÷ 1 = 1 kVA). At low values of power factor, more
apparent power needs to be transferred to get the same real power. To get 1 kW of real power
at 0.2 power factor, 5 kVA of apparent power needs to be transferred (1 kW ÷ 0.2 = 5 kVA).
This apparent power must be produced and transmitted to the load in the conventional
fashion, and is subject to the usual distributed losses in the production and transmission
processes.
Electrical loads consuming alternating current power consume both real power and reactive
power. The vector sum of real and reactive power is the apparent power. The presence of
reactive power causes the real power to be less than the apparent power, and so, the electric
load has a power factor of less than 1.
1.1.7 Power factor correction of linear loads:
It is often desirable to adjust the power factor of a system to near 1.0. This power factor
correction (PFC) is achieved by switching in or out banks of inductors or capacitors. For
example the inductive effect of motor loads may be offset by locally connected capacitors.
When reactive elements supply or absorb reactive power near the load, the apparent power
is reduced.
Power factor correction may be applied by an electrical power transmission utility to
improve the stability and efficiency of the transmission network. Correction equipment may
be installed by individual electrical customers to reduce the costs charged to them by their
electricity supplier. A high power factor is generally desirable in a transmission system to
reduce transmission losses and improve voltage regulation at the load.
Power factor correction brings the power factor of an AC power circuit closer to 1 by
supplying reactive power of opposite sign, adding capacitors or inductors which act to cancel
the inductive or capacitive effects of the load, respectively. For example, the inductive effect
of motor loads may be offset by locally connected capacitors. If a load had a capacitive
value, inductors (also known as reactors in this context) are connected to correct the power
factor. In the electricity industry, inductors are said to consume reactive power and
capacitors are said to supply it, even though the reactive power is actually just moving back
and forth on each AC cycle.
The reactive elements can create voltage fluctuations and harmonic noise when switched on
or off. They will supply or sink reactive power regardless of whether there is a corresponding
load operating nearby, increasing the system's no-load losses. In a worst case, reactive
elements can interact with the system and with each other to create resonant conditions,
resulting in system instability and severe overvoltage fluctuations. As such, reactive

15
elements cannot simply be applied at will, and power factor correction is normally subject
to engineering analysis.
An automatic power factor correction unit is used to improve power factor. A power factor
correction unit usually consists of a number of capacitors that are switched by means of
contactors. These contactors are controlled by a regulator that measures power factor in an
electrical network. To be able to measure power factor, the regulator uses a current
transformer to measure the current in one phase.
Depending on the load and power factor of the network, the power factor controller will
switch the necessary blocks of capacitors in steps to make sure the power factor stays above
a selected value (usually demanded by the energy supplier), say 0.9.
Instead of using a set of switched capacitors, an unloaded synchronous motor can supply
reactive power. The reactive power drawn by the synchronous motor is a function of its field
excitation. This is referred to as a synchronous condenser. It is started and connected to the
electrical network. It operates at a leading power factor and puts VARS onto the network as
required to support a system’s voltage or to maintain the system power factor at a specified
level.
The condenser’s installation and operation are identical to large electric motors. Its principal
advantage is the ease with which the amount of correction can be adjusted; it behaves like
an electrically variable capacitor. Unlike capacitors, the amount of reactive power supplied
is proportional to voltage, not the square of voltage; this improves voltage stability on large
networks. Synchronous condensers are often used in connection with high voltage direct
current transmission projects or in large industrial plants such as steel mills.
1.1.8 Non-linear loads:
A non-linear load on a power system is typically a rectifier (such as used in a power supply),
or some kind of arc discharge device such as a fluorescent lamp, electric welding machine,
or arc furnace. Because current in these systems is interrupted by a switching action, the
current contains frequency components that are multiples of the power system frequency.
Distortion power factor is a measure of how much the harmonic distortion of a load current
decreases the average power transferred to the load.
1.1.9 Non-sinusoidal components:
Non-linear loads change the shape of the current waveform from a sine wave to some other
form. Non-linear loads create harmonic currents in addition to the original (fundamental
frequency) AC current. Filters consisting of linear capacitors and inductors can prevent
harmonic currents from entering the supplying system.
In linear circuits having only sinusoidal currents and voltages of one frequency, the power
factor arises only from the difference in phase between the current and voltage. This is
"displacement power factor". The concept can be generalized to a total, distortion, or true
power factor where the apparent power includes all harmonic components. This is of

16
importance in practical power systems which contain non-linear loads such as rectifiers,
some forms of electric lighting, electric arc furnaces, welding equipment, switched-mode
power supplies and other devices.
A typical multimeter will give incorrect results when attempting to measure the AC current
drawn by a non-sinusoidal load; the instruments sense the average value of a rectified
waveform. The average response is then calibrated to the effective, RMS value. An RMS
sensing multimeter must be used to measure the actual RMS currents and voltages (and
therefore apparent power). To measure the real power or reactive power, a wattmeter
designed to work properly with non-sinusoidal currents must be used.
1.1.10 Distortion power factor:
The distortion power factor' describes how the harmonic distortion of a load current
decreases the average power transferred to the load.
THDi is the total harmonic distortion of the load current. This definition assumes that the
voltage stays undistorted (sinusoidal, without harmonics). This simplification is often a good
approximation in practice. I1,rms is the fundamental component of the current and Irms is
the total current - both are root mean square-values.
The result when multiplied with the displacement power factor (DPF) is the overall, true
power factor or just power factor (PF):

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CHAPTER: 2
MODEL EXPLANATION
2.1 Block Diagram and Schematic Diagram:

19
FIGURE 4: SCHEMATIC DIAGRAM

20
2.2 Description:
2.2.1 Power Supply:
The circuit uses standard power supply comprising of a step-down transformer from 230Vto
12V and 4 diodes forming a bridge rectifier that delivers pulsating dc which is then filtered
by an electrolytic capacitor of about 470µF to 1000µF. The filtered dc being unregulated,
IC LM7805 is used to get 5V DC constant at its pin no 3 irrespective of input DC varying
from 7V to 15V. The input dc shall be varying in the event of input ac at 230volts section
varies from 160V to 270V in the ratio of the transformer primary voltage V1 to secondary
voltage V2 governed by the formula V1/V2=N1/N2. As N1/N2 i.e. no. of turns in the
primary to the no. of turns in the secondary remains unchanged V2 is directly proportional
to V1.Thus if the transformer delivers 12V at 220V input it will give 8.72V at
160V.Similarly at 270V it will give 14.72V.Thus the dc voltage at the input of the regulator
changes from about 8V to 15V because of A.C voltage variation from 160V to 270V the
regulator output will remain constant at 5V.
The regulated 5V DC is further filtered by a small electrolytic capacitor of 10µF for any
noise so generated by the circuit. One LED is connected of this 5V point in series with a
current limiting resistor of 330Ω to the ground i.e., negative voltage to indicate 5V power
supply availability. The unregulated 12V point is used for other applications as and when
required.
2.2.2 Standard Connection to 8051 Series Microcontroller:
ATMEL series of 8051 family of micro controllers need certain standard connections. The
actual number of the Microcontroller could be “89C51” , “89C52”, “89S51”, “89S52”, and
as regards to 20 pin configuration a number of “89C2051”. The 4 set of I/O ports are used
based on the project requirement. Every microcontroller requires a timing reference for its
internal program execution therefore an oscillator needs to be functional with a desired
frequency to obtain the timing reference as t =1/f.
A crystal ranging from 2 to 20 MHz is required to be used at its pin number 18 and 19 for
the internal oscillator. It may be noted here the crystal is not to be understood as crystal
oscillator It is just a crystal, while connected to the appropriate pin of the microcontroller it
results in oscillator function inside the microcontroller. Typically 11.0592 MHz crystal is
used in general for most of the circuits using 8051 series microcontroller. Two small value
ceramic capacitors of 33pF each is used as a standard connection for the crystal as shown in
the circuit diagram.

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Reset:
Pin no 9 is provided with an resset arrangement by a combination of an electrolytic capacitor
and a register forming RC time constant. At the time of switch on, the capacitor gets charged,
and it behaves as a full short circuit from the positive to the pin number 9. After the capacitor
gets fully charged the current stops flowing and pin number 9 goes low which is pulled down
by a 10k resistor to the ground. This arrangement of reset at pin 9 going high initially and
then to logic 0 i.e., low helps the program execution to start from the beginning. In absence
of this the program execution could have taken place arbitrarily anywhere from the program
cycle. A pushbutton switch is connected across the capacitor so that at any given time as
desired it can be pressed such that it discharges the capacitor and while released the capacitor
starts charging again and then pin number 9 goes to high and then back to low, to enable the
program execution from the beginning. This operation of high to low of the reset pin takes
place in fraction of a second as decided by the time constant R and C.
For example: A 10µF capacitor and a 10kΩ resistor would render a 100ms time to pin
number 9 from logic high to low, there after the pin number 9 remains low.
External Access (EA):
Pin no 31 of 40 pin 8051 microcontroller termed as EA¯ is required to be connected to 5V
for accessing the program form the on-chip program memory. If it is connected to ground
then the controller accesses the program from external memory. However as we are using
the internal memory it is always connected to +5V.
2.2.3 Brief Description of Working of Relay:
A relay is an electrically operated switch. Current flowing through the coil of the relay
creates a magnetic field which attracts a lever and changes the switch contacts. The coil
current can be on or off so relays have two switch positions and most have double throw
(changeover) switch contacts. Relays allow one circuit to switch a second circuit which can
be completely separate from the first. For example a low voltage battery circuit can use a
relay to switch a 230V AC mains circuit. There is no electrical connection inside the relay
between the two circuits; the link is magnetic and mechanical.
FIGURE 5: WORKING OF RELAY
2.2.4 ULN 2003 Relay Driver IC:

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ULN2003 is an IC which is used to interface relay with the microcontroller since the output
of the micro controller is maximum 5V with too little current delivery and is not practicable
to operate a relay with that voltage. ULN2003 is a relay driver IC consisting of a set of
Darlington transistors. If logic high is given to the IC as input then its output will be logic
low but not the vice versa. Here in ULN2003 pins 1 to 7 are IC inputs and 10 to 16 are IC
outputs. If logic 1 is given to its pin no 1 the corresponding pin 16 goes low. If a relay coil
is connected from +ve to the output pin of the uln2003,(the relay driver) then the relay
contacts change their position from normally open to close the circuit as shown below for
the load on (say a lamp to start glowing). If logic 0 is given at the input the relay switches
off. Similarly upto seven relays can be used for seven different loads to be switched on by
the normally open(NO) contact or switched off by the normally closed contact(NC)
Load off Load on
FIGURE 6: RELAY DRIVER
Comparator:
How an op-amp can be used as a comparator?
Potential dividers are connected to the inverting and non inverting inputs of the op-
amp to give some voltage at these terminals. Supply voltage is given to +Vss and –Vss is
connected to ground. The output of this comparator will be logic high (i.e., supply voltage)
if the non-inverting terminal input is greater than the inverting terminal input of the
comparator i.e., Non inverting input (+) > inverting input (-) = output is logic high
If the inverting terminal input is greater than the non-inverting terminal input then the output
of the comparator will be logic low (i.e., gnd.) i.e., inverting input (-) > Non inverting input
(+) = output is logic low.

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2.3 Operation Explanation:
Connections:
The output of power supply which is 5v is connected to the 40th
pin of microcontroller and
gnd to the 20th
pin or pin 20 of microcontroller. Port 0.1 to 0.4 of microcontroller is
connected to Pin 1to 4 of relay driver IC ULN2003. Port 0.5 to 0.7 of microcontroller is
connected to Pin 4,5 and 6 of LCD display. Port 2.0 to 2.7 of microcontroller is connected
to Pin 7 to 14 of data pins of LCD display. Port 3.1 of microcontroller is connected to output
of the OP-Amp (A) LM339. Port 3.3 of microcontroller is connected to output of OP-Amp
(B) LM339.
Working:
The output of the regulator 7805 is given to the Microcontroller 40th
pin. The pulsating dc
is fed to R11 and R24 Resistor’s. The unregulated voltage is fed to 7812. 7805 output which
is 5v is fed to 40th
pin of Microcontroller. The output of the 7812 regulator is 12v and is fed
to op-Amp. In this circuit we have another bridge rectifier it gives an output as pulsating dc
corresponding to the current flowing across the load. The LCD display is connected to
corresponding pins. Relay driver drive’s relay’s and the contacts of relays switch ON the
shunt capacitors.
Description of ZVS and ZCS:
In order to generate ZVS (Zero Voltage Sensing) pulses first we need to step down the
supply voltage to 12 V and then it is converted into pulsating D.C. Then with the help of
potential divider the voltage of 3 V is taken, which is given to a comparator LM339 part A.
The comparator generates the zero crossing pulses by comparing this pulsating D.C with a
constant D.C of 0.6 V forward voltage drop across a silicon diode.
Similarly for ZCS (Zero Current Sense) the voltage drop proportional to the load current
across a resistor of 10R/10W is taken and is stepped up by a CT to feed to a bridge rectifier
to generate pulsating dc for the comparator to develop ZCS as explained above like ZVS.
The zero crossing pulses from a pulsating D.C both for ZVS and ZCS are shown in the figure
below.

25
This circuit consists of DC power supply unit, zero voltage crossing detectors, Micro-
controller, LCD display, Relays and Capacitor bank and Load circuit. Let us see how it
operates. The required DC power supply for Micro-controller and other peripherals is supplied
by the DC power supply.
For the calculation of the power factor by the Micro-controller we need digitized voltage and
current signals. The voltage signal from the mains is taken and it is converted into pulsating
DC by bridge rectifier and is given to a comparator which generates the digital voltage signal.
Similarly the current signal is converted into the voltage signal by taking the voltage drop of
the load current across a resistor of 10 ohms. This A.C signal is again converted into the digital
signal as done for the voltage signal. Then these digitized voltage and current signals are sent
to the micro-controller. The micro-controller calculates the time difference between the zero
crossing points of current and voltage, which is directly proportional to the power factor and
it determines the range in which the power factor is. Micro-controller sends information
regarding time difference between current and voltage and power factor to the LCD display
to display them, Depending on the range it sends the signals to the relays through the relay
driver. Then the required numbers of capacitors are connected in parallel to the load. By this
the power factor will be improved and saving in power is displayed on the 16x2 LCD.
Note:
The capacitor value required and the extent of PF improvement taking place are not the aim
of the project. Such parameters are to be taken into consideration once it is developed to a
commercial product. Load current magnitude and KVR requirement of capacitors are of
paramount importance then. Our project does not measure the load current magnitude nor the
KVR requirement of the capacitors but simply considers the time difference between the
voltage and the current. We simply follow the following table to read the delay time and switch
on as many capacitors as required across the inductive load to bring the pf to near unity as
decided by the program .In order to simplify we have taken 4 capacitors only and have taken
4 sets of time delay range. Thus between 0.5 to 921 uSec (0.9ms) delay for average pf display
of (0.975916762) pf by switching 1st relay. Then from 921 to 1843 u Sec (1.8ms) delay for
average pf of (0.891006524) pf by switching 2nd relay. And so on for 3rd and 4th relay...
Delay Delay Angle PF
Time in mS (90/5)*Time in mS COS(angle*PIE/180)
0.5 9 0.987688341
0.6 10.8 0.982287251

26
0.7 12.6 0.975916762 Average PF display
0.8 14.4 0.968583161
0.9 16.2 0.960293686 1st relay
1.1 19.8 0.940880769
1.2 21.6 0.929776486
1.3 23.4 0.917754626
1.4 25.2 0.904827052
1.5 27 0.891006524 Average PF display
1.6 28.8 0.87630668
1.7 30.6 0.860742027
1.8 32.4 0.844327926 2nd relay
1.9 34.2 0.827080574
2 36 0.809016994
2.1 37.8 0.790155012
2.2 39.6 0.770513243
2.3 41.4 0.75011107
2.5 45 0.707106781
2.6 46.8 0.684547106
2.7 48.6 0.661311865 3rd relay
2.8 50.4 0.63742399
2.9 52.2 0.612907054
3 54 0.587785252
3.1 55.8 0.562083378
3.2 57.6 0.535826795
3.4 61.2 0.481753674
3.5 63 0.4539905
3.6 64.8 0.425779292 4th relay
Table 1: The Delay Time and Switch ON as Many Capacitors
Note: For a 50 Hz supply half cycle is 10 mS =180degree or 90deg=5mS -
2.5 Layout Diagram:

27
FIGURE 7: LAYOUT
2.6 Hardware Requirement:

28
2.6.1 HARDWARE COMPONENTS:
1. TRANSFORMER (230 – 12 V AC)
2. VOLTAGE REGULATOR
3. RECTIFIER
4. FILTER
5. MICROCONTROLLER (AT89S52/AT89C51)
6. RELAY
7. RELAY DRIVER
8. PUSH BUTTONS
9. LCD
10. LM339
11. CURRENT TRANSFORMER
12. INDUCTIVE LOAD
13. SHUNT CAPACITOR
14. LED
15. 1N4007 / 1N4148
16. RESISTOR
17. CAPACITOR
2.7 Software Requirements:

29
Introduction to KEIL Micro vision (IDE):
Keil an ARM Company makes C compilers, macro assemblers, real-time kernels,
debuggers, simulators, integrated environments, evaluation boards, and emulators for
ARM7/ARM9/Cortex-M3, XC16x/C16x/ST10, 251, and 8051 MCU families.
Keil development tools for the 8051 Microcontroller Architecture support every
level of software developer from the professional applications engineer to the student just
learning about embedded software development. When starting a new project, simply select
the microcontroller you use from the Device Database and the µVision IDE sets all compiler,
assembler, linker, and memory options for you.
Keil is a cross compiler. So first we have to understand the concept of compilers and
cross compilers. After then we shall learn how to work with keil.
Concept of COMPILER:
Compilers are programs used to convert a High Level Language to object code.
Desktop compilers produce an output object code for the underlying microprocessor, but not
for other microprocessors. I.E the programs written in one of the HLL like ‘C’ will compile
the code to run on the system for a particular processor like x86 (underlying microprocessor
in the computer). For example compilers for Dos platform is different from the Compilers
for Unix platform So if one wants to define a compiler then compiler is a program that
translates source code into object code.
The compiler derives its name from the way it works, looking at the entire piece of
source code and collecting and reorganizing the instruction. See there is a bit little difference
between compiler and an interpreter. Interpreter just interprets whole program at a time
while compiler analyses and execute each line of source code in succession, without looking
at the entire program.
The advantage of interpreters is that they can execute a program immediately.
Secondly programs produced by compilers run much faster than the same programs executed
by an interpreter. However compilers require some time before an executable program
emerges. Now as compilers translate source code into object code, which is unique for each
type of computer, many compilers are available for the same language.
Concept of CROSS COMPILER:
A cross compiler is similar to the compilers but we write a program for the target
processor (like 8051 and its derivatives) on the host processors (like computer of x86). It
means being in one environment you are writing a code for another environment is called
cross development. And the compiler used for cross development is called cross
compiler. So the definition of cross compiler is a compiler that runs on one computer but
produces object code for a different type of computer.
KEIL C CROSS COMPILER
KEIL is a German based Software development company. It provides several
development tools like

30
• IDE (Integrated Development environment)
• Project Manager
• Simulator
• Debugger
• C Cross Compiler, Cross Assembler, Locator/Linker
The Keil ARM tool kit includes three main tools, assembler, compiler and linker. An
assembler is used to assemble the ARM assembly program. A compiler is used to compile
the C source code into an object file. A linker is used to create an absolute object module
suitable for our in-circuit emulator
.
Building an Application in µVision2:
To build (compile, assemble, and link) an application in µVision2, you must:
1. Select Project -(forexample,166EXAMPLESHELLOHELLO.UV2).
2. Select Project - Rebuild all target files or Build target.µVision2 compiles, assembles,
and links the files in your project.
Creating Your Own Application in µVision2:
To create a new project in µVision2, you must:
1. Select Project - New Project.
2. Select a directory and enter the name of the project file.
3. Select Project - Select Device and select an 8051, 251, or C16x/ST10 device from
the Device Database™.
4. Create source files to add to the project.
5. Select Project - Targets, Groups, Files. Add/Files, select Source Group1, and add the
source files to the project.
6. Select Project - Options and set the tool options. Note when you select the target
device from the Device Database™ all special options are set automatically. You
typically only need to configure the memory map of your target hardware. Default
memory model settings are optimal for most applications.
7. Select Project - Rebuild all target files or Build target.
Debugging an Application in µVision2:
To debug an application created using µVision2, you must:
1. Select Debug - Start/Stop Debug Session.
2. Use the Step toolbar buttons to single-step through your program. You may enter G,
main in the Output Window to execute to the main C function.

31
3. Open the Serial Window using the Serial #1 button on the toolbar.
Debug your program using standard options like Step, Go, Break, and so on.
Starting µVision2 and creating a Project:
µVision2 is a standard Windows application and started by clicking on the program
icon. To create a new project file select from the µVision2 menu Project – New Project….
This opens a standard Windows dialog that asks you for the new project file name. We
suggest that you use a separate folder for each project. You can simply use the icon Create
New Folder in this dialog to get a new empty folder. Then select this folder and enter the
file name for the new project, i.e. Project1. µVision2 creates a new project file with the name
PROJECT1.UV2 which contains a default target and file group name. You can see these
names in the Project.
Window – Files:
Now use from the menu Project – Select Device for Target and select a CPU for your
project. The Select Device dialog box shows the µVision2 device data base. Just select the
microcontroller you use. We are using for our examples the Philips 80C51RD+ CPU. This
selection sets necessary tool Options for the 80C51RD+ device and simplifies in this way
the tool Configuration.
Building Projects and Creating a HEX Files:
Typical, the tool settings under Options – Target are all you need to start a new
application. You may translate all source files and line the application with a click on the
Build Target toolbar icon. When you build an application with syntax errors, µVision2 will
display errors and warning messages in the Output Window – Build page. A double click on
a message line opens the source file on the correct location in a µVision2 editor window.
Once you have successfully generated your application you can start debugging.
After you have tested your application, it is required to create an Intel HEX file to
download the software into an EPROM programmer or simulator. µVision2 creates HEX
files with each build process when Create HEX files under Options for Target – Output is
enabled. You may start your PROM programming utility after the make process when you
specify the program under the option Run User Program #1.
CPU Simulation:
µVision2 simulates up to 16 Mbytes of memory from which areas can be mapped for read,
write, or code execution access. The µVision2 simulator traps and reports illegal memory
accesses. In addition to memory mapping, the simulator also provides support for the
integrated peripherals of the various 8051 derivatives. The on-chip peripherals of the CPU
you have selected are configured from the Device.
Database selection:

32
You have made when you create your project target. Refer to page 58 for more Information
about selecting a device. You may select and display the on-chip peripheral components
using the Debug menu. You can also change the aspects of each peripheral using the controls
in the dialog boxes.
Start Debugging:
You start the debug mode of µVision2 with the Debug – Start/Stop Debug Session
Command. Depending on the Options for Target – Debug Configuration, µVision2 will load
the application program and run the start-up code µVision2 saves the editor screen layout
and restores the screen layout of the last debug session. If the program execution stops,
µVision2 opens an editor window with the source text or shows CPU instructions in the
disassembly window. The next executable statement is marked with a yellow arrow. During
debugging, most editor features are still available.
For example, you can use the find command or correct program errors. Program source text
of your application is shown in the same windows. The µVision2 debug mode differs from
the edit mode in the following aspects:
_ The “Debug Menu and Debug Commands” described on page 28 are available. The
additional debug windows are discussed in the following.
_ The project structure or tool parameters cannot be modified. All build commands are
disabled.
Disassembly Window:
The Disassembly window shows your target program as mixed source and assembly
program or just assembly code. A trace history of previously executed instructions may be
displayed with Debug – View Trace Records. To enable the trace history, set Debug –
Enable/Disable Trace Recording.
If you select the Disassembly Window as the active window all program step commands
work on CPU instruction level rather than program source lines. You can select a text line
and set or modify code breakpoints using toolbar buttons or the context menu commands.
You may use the dialog Debug – Inline Assembly… to modify the CPU instructions. That
allows you to correct mistakes or to make temporary changes to the target program you are
debugging. Numerous example programs are included to help you get started with the most
popular embedded 8051 devices.
The Keil µVision Debugger accurately simulates on-chip peripherals (I²C, CAN, UART,
SPI, Interrupts, I/O Ports, A/D Converter, D/A Converter, and PWM Modules) of your 8051
device. Simulation helps you understand hardware configurations and avoids time wasted
on setup problems. Additionally, with simulation, you can write and test applications before
target hardware is available.
EMBEDDED C:

33
Use of embedded processors in passenger cars, mobile phones, medical equipment,
aerospace systems and defence systems is widespread, and even everyday domestic
appliances such as dish washers, televisions, washing machines and video recorders now
include at least one such device.
Because most embedded projects have severe cost constraints, they tend to use low-
cost processors like the 8051 family of devices considered in this book. These popular chips
have very limited resources available most such devices have around 256 bytes (not
megabytes!) of RAM, and the available processor power is around 1000 times less than that
of a desktop processor. As a result, developing embedded software presents significant new
challenges, even for experienced desktop programmers. If you have some programming
experience - in C, C++ or Java - then this book and its accompanying CD will help make
your move to the embedded world as quick and painless as possible.
2.8 Coding:

48
2.9 Estimation of Materials:
COMPONENT NAME QUANTITY
Resistors
330R 1
10K 2
3.3K 1
4.7K 6
22K 2
1K 6
10R/10W 2
10K PRESET 1
10K SIP RESISTOR 1
Capacitors
470uF /1000uF/35V (PREFERABLE) 1
10uF/63V 2
33pF Ceramic 2
2uF/400V (FAN CAPACITOR) 4
Integrated Circuits
7805 1
7812 1
AT89S52 1
LM339 1
ULN2003 1
IC Bases
40-PIN BASE 1
16-PIN BASE 1
14-PIN BASE 1
DIODE
1N4007 9
1N4148 2
Miscellaneous
CRYSTAL 11.0592MHz 1
LED-RED 5
2-PIN PUSH BUTTON 1
BULB 100W 1
BULB HOLDER 1
CHOKE 1
CURRENT TRANSFORMER (0-12V 500mA Transformer) 1
12V RELAY 4
LCD 16X2 1
PCB CONNECTOR 2-PIN 8
SLIDE SWITCHES 2
POWER CORD 1
AC CONNECTOR 2-PIN 1
TRANSFORMER 12V, 1 AMPERE MUST 1
MALE BURGE 2-PIN 2
FEMALE BURGE 2-PIN 2
FEMALE BURGE 16-PIN 1
MALE BURGE 16-PIN 1(INCLUDED WITH LCD)

49
HEAT SINK 2
SCREW NUT FOR HEAT SINK 2
COPPER WIRE FOR LOAD
PLAIN PCB 1
SOLDERING LED (50 gm)
CONNECTING WIRE
Table 2: Estimation of Material

50
CHAPTER: 3
ENERGY CONSERVATION IN POWER GENERATION

51
3.1 Energy conservation According to Conventional Sources:
The availability of reliable and economic forms of energy is an important prerequisite for
the economic and social development of a nation. The per capita consumption of power in
developed countries like U.S.A is approx. 14500 kWh/year. The per capita consumption of
power in India is still approx. 750 kWh/year which is lower than China (approx. 2600
kWh/year). The installed generation capacity of India is about 1, 53, 000 MW. The power
requirement of our country is projected to shoot up to 3, 00 , 000 MW in the next decade.
Simultaneously the population rise at the rate of 1.8% which increase use of energy. India
is facing a power shortage of 9.8% with peak shortage use of 16.6% and this scene is to be
changed for the worse in the coming years. Presently the shortage of peak load power in
India is estimated to around 19%. To meet the demand, India is forced to add new generating
installations. Present cost of erection of a thermal plant is more than Rs. 7 crore/MW.
India has 16% of world population, but less than 1% of world’s energy resources. Due to
resources crunch and capital investment problem, installed capacity added in every five year
plan is less than the targeted value. This is bound to give large gap between demand and
supply. This gap becomes a matter of national concern today. There is a need of power
conservation and the efficient utilization of the available power. Every watt of power saved
by efficient equipment/appliance is much more than each watt generated. USA, Japan and
western Europe have improved their overall energy efficiency by 30% to 40% in last 20%
years. However, initiatives by India in this area leave much to desire.
The cost of energy inputs is increasing day by day. The toughest task for any successful
industry or power station is to find ways and means to optimize the use of energy to get
position in developed country. When energy is conserved, the rewards are twofold. There is
an immediate reward, a saving of money and a long term reward, the saving of our earth’s
resources for future generations.
Energy conservation auditors have to look at every nook and corner to achieve the objective
of finding wastage of energy. Various utilities of power station which form part of the energy
input to any process need careful attentions. Some of the guidelines given here to contribute
for the cause of energy conservation.
Depending on the process and plant design, other area can be explored for energy
conservation. But the best time to optimize the energy consumption is at design stage. So
proper design can give result from the start.

52
3.2 Use of Co-Generation Plant:
A cogeneration system is the sequential or simultaneous generation of multiple forms of
useful energy (usually mechanical and thermal) in a single, integrated system. CHP systems
consist of a number of individual components – prime mover (heat engine), generator, heat
recovery, and electrical interconnection – configured into an integrated whole. The type of
equipment that drives the overall system (i.e. the prime mover) typically identifies the CHP
system. Prime movers for CHP systems include reciprocating engines, combustion or gas
turbines, steam turbines, micro-turbines, and fuel cells. These prime movers are capable of
burning a variety of fuels, including natural gas, coal, oil, and alternative fuels to produce
shaft power or mechanical energy. Although mechanical energy from the prime mover is
most often used to drive a generator to produce electricity, it can also be used to drive
rotating equipment such as compressors, pumps, and fans. Thermal energy from the system
can be used in direct process applications or indirectly to produce steam, hot water, hot air
for drying, or chilled water for process cooling.
FIGURE 8: ENERGY EFFICIENCY ADVANTAGE OF A COGENERATION
Figure 1 shows the efficiency advantage of CHP compared to the conventional central
station power generation and on-site boilers. When both thermal and electrical processes are
compared, a CHP system typically requires only three-fourth the primary energy compared
to separate heat and power systems. This reduced primary fuel consumption is the main
environmental benefit of CHP, since burning the same amount of fuel more efficiently
means fewer emissions for the same level of output.
3.2.1 The Benefits of Cogeneration:
Provided the cogeneration is optimized in the way described above (i.e. sized according to
the heat demand), the following benefits can be obtained:
▪ Increased efficiency of energy conversion and use
▪ Lower emissions to the environment, in particular of CO2, the main greenhouse gas
▪ In some cases, biomass fuels and some waste materials such as refinery gases, process
or agricultural waste (either an aerobically digested or gasified), are used. These substances

53
which serve as fuels for cogeneration schemes, increases the cost-effectiveness and reduces
the need for waste disposal.
▪ Large cost savings, providing additional competitiveness for industrial and
commercial users while offering affordable heat for domestic users also
▪ An opportunity to move towards more decentralized forms of electricity generation,
where plants are designed to meet the needs of local consumers, providing high efficiency,
avoiding transmission losses and increasing flexibility in system use. This will particularly
be the case if natural gas is the energy carrier
▪ An opportunity to increase the diversity of generation plant, and provide competition
in generation. Cogeneration provides one of the most important vehicles for promoting
liberalization in energy markets.
3.3 Types of Cogeneration System:
Various types of cogeneration systems: steam turbine cogeneration system, gas turbine
cogeneration system, and reciprocating engine cogeneration system. It also includes a
classification of cogeneration systems on the basis of the sequence of energy used.
3.3.1 Steam Turbine Cogeneration System:
Steam turbines are one of the most versatile and oldest prime mover technologies still in
general production. Power generation using steam turbines has been in use for about 100
years, when they replaced reciprocating steam engines due to their higher efficiencies and
lower costs. The capacity of steam turbines can range from 50 kW to several hundred MWs
for large utility power plants. Steam turbines are widely used for combined heat and power
(CHP) applications. The thermodynamic cycle for the steam turbine is the Rankine cycle.
The cycle is the basis for conventional power generating stations and consists of a heat
source (boiler) that converts water to high-pressure steam. In the steam cycle, water is first
pumped to medium to high pressure. It is then heated to the boiling temperature
corresponding to the pressure, boiled (heated from liquid to vapor), and then most frequently
superheated (heated to a temperature above that of boiling). A multistage turbine expands
the pressurized steam to lower pressure and the steam is then exhausted either to a condenser
at vacuum conditions or into an intermediate temperature steam distribution system that
delivers the steam to the industrial or commercial application. The condensate from the
condenser or from the steam utilization system returns to the feed water pump for
continuation of the cycle. The two types of steam turbines most widely used are the
backpressure and the extraction condensing types. The choice between backpressure turbine
and extraction-condensing turbine depends mainly on the quantities of power and heat,
quality of heat, and economic factors. The extraction points of steam from the turbine could
be more than one, depending on the temperature levels of heat required by the processes.
3.3.2 Gas Turbine Cogeneration System:

54
Gas turbine systems operate on the thermodynamic cycle known as the Brayton cycle. In a
Brayton cycle, atmospheric air is compressed, heated, and then expanded, with the excess
of power produced by the turbine or expander over that consumed by the compressor used
for power generation. Gas turbine cogeneration systems can produce all or a part of the
energy requirement of the site, and the energy released at high temperature in the exhaust
stack can be recovered for various heating and cooling applications. Though natural gas is
most commonly used, other fuels such as light fuel oil or diesel can also be employed. The
typical range of gas turbines varies from a fraction of a MW to around 100 MW. Gas turbine
cogeneration has probably experienced the most rapid development in recent years due to
the greater availability of natural gas, rapid progress in the technology, significant reduction
in installation costs, and better environmental performance. Furthermore, the gestation
period for developing a project is shorter and the equipment can be delivered in a modular
manner. Gas turbines have a short start-up time and provide the flexibility of intermittent
operation. Though they have a low heat to power conversion efficiency, more heat can be
recovered at higher temperatures. If the heat output is less than that required by the user, it
is possible to have supplementary natural gas firing by mixing additional fuel to the oxygen-
rich exhaust gas to boost the thermal output more efficiently.
3.3.3 Reciprocating Engine Cogeneration System:
Reciprocating engines are well suited to a variety of distributed generation applications,
industrial, commercial, and institutional facilities for power generation and CHP.
Reciprocating engines start quickly, follow load well, have good part- load efficiencies, and
generally have high reliabilities. In many cases, multiple reciprocating engine units further
increase overall plant capacity and availability. Reciprocating engines have higher electrical
efficiencies than gas turbines of comparable size, and thus lower fuel-related operating costs.
In addition, the first costs of reciprocating engine gen sets are generally lower than gas
turbine gen sets up to 3-5 MW in size. Reciprocating engine maintenance costs are generally
higher than comparable gas turbines, but the maintenance can often be handled by in-house
staff or provided by local service organizations. Potential distributed generation applications
for reciprocating engines include standby, peak shaving, grid support, and CHP applications
in which hot water, low-pressure steam, or waste heat- fired absorption chillers are required.
Reciprocating engines are also used extensively as direct mechanical drives in applications
such as water pumping, air and gas compression and chilling/refrigeration. There are four
sources of usable waste heat from a reciprocating engine: exhaust gas, engine jacket-cooling
water, lube oil cooling water, and turbocharger cooling. Recovered heat is generally in the
form of hot water or low-pressure steam (<30 psig). The high temperature exhaust can
generate medium pressure steam (up to about 150 psig), but the hot exhaust gas contains
only about one half of the available thermal energy from a reciprocating engine. Some
industrial CHP applications use the engine exhaust gas directly for process drying.
Generally, the hot water and low pressure steam produced by reciprocating engine CHP
systems is appropriate for low temperature process needs, space heating, potable water
heating, and to drive absorption chillers providing cold water, air conditioning, or
refrigeration.
Nominal
Range
Electrical
Generation
Efficiencies, %

55
Prime Mover
in
Cogeneration
Package
(Electrical) Heat Rate
(kcal
/ kWh)
Electrical
Conversion
Thermal
Recovery
Overall
Cogeneration
Smaller
Reciprocating
Engines
10 – 500
kW
2650 - 6300 20-32 50 74-82
Larger
Reciprocating
Engines
500 – 3000
kW
2400 - 3275 26-36 50 76-86
Diesel
Engines
10-3000
kW
2770 - 3775 23-38 50 73-88
Smaller Gas
Turbines
800-10000
kW
2770-3525 24-31 50 74-81
Larger Gas
Turbines
10-20 MW 2770-3275 26-31 50 78-81
Steam
Turbines
10-100 MW 2520-5040 17-34 - -
Table 3: Typical cogeneration performance parameters
3.3.4 Option Checklist:
The most important energy efficiency options for cogeneration,
▪ Using the exhaust gas to heat the air from the compressor (mainly used in cold weather
conditions).
▪ Divide the compressor into two parts and cool the air between the two parts.
▪ Divide the turbine into two parts and reheat the gas between the two parts by passing
the gas through additional burners and combustors located between the two parts.
▪ Cooling the inlet air. This is mainly used in hot weather conditions;
▪ Reducing the humidity of the inlet air.
▪ Increasing the pressure of the air at the discharge of the air compressor.
▪ Inject steam or water into the combustors or turbine.
▪ Wash or otherwise clean the fouling from the blades of the air compressor and turbine
at regular intervals and
▪ Combinations of the above methods.

56
3.4 Mini Hydropower Plant:
Use running water to generate electricity, whether it's a small stream or a larger river.
Small or micro hydroelectricity systems, also called hydropower systems or just hydro
systems, can produce enough electricity for lighting and electrical appliances in an average
home.
All streams and rivers flow downhill. Before the water flows down the hill, it has potential
energy because of its height. Hydro power systems convert this potential energy into kinetic
energy in a turbine, which drives a generator to produce electricity. The greater the height
and the more water there is flowing through the turbine, the more electricity can be
generated.
The amount of electricity a system actually generates also depends on how efficiently it
converts the power of the moving water into electrical power.
Small-scale hydropower is one of the most cost-effective and reliable energy technologies
to be considered for providing clean electricity generation. In particular, the key advantages
that small hydro has over wind, wave and solar power are:
1) A high efficiency (70 - 90%), by far the best of all energy technologies.
2) A high capacity factor (typically >50%), compared with 10% for solar and 30% for
wind.
3) A high level of predictability, varying with annual rainfall patterns.
4) Slow rate of change; the output power varies only gradually from day to day (not
from minute to minute).
5) It is a long-lasting and robust technology; systems can readily be engineered to last
for 50 years or more.
It is also environmentally benign. Small hydro is in most cases 'run-of-river'; in other words
any dam or barrage is quite small, usually just a weir, and little or no water is stored.
Therefore run-of-river installations do not have the same kinds of adverse effect on the local
environment as large-scale hydro.
Hydraulic power can be captured wherever a flow of water falls from a higher level to a
lower level. This may occur where a stream runs down a hillside, or a river passes over a
waterfall or man-made weir, or where a reservoir discharges water back into the main river.
The vertical fall of the water, known as the “head”, is essential for hydropower generation;
fast-flowing water on its own does not contain sufficient energy for useful power production
except on a very large scale, such as offshore marine currents. Hence two quantities are
required: a Flow Rate of water Q, and a Head H. It is generally better to have more head
than more flow, since this keeps the equipment smaller.
The Gross Head (H) is the maximum available vertical fall in the water, from the upstream
level to the downstream level. The actual head seen by a turbine will be slightly less than

57
the gross head due to losses incurred when transferring the water into and away from the
machine. This reduced head is known as the Net Head.
Sites where the gross head is less than 10 m would normally be classed as “low head”. From
10-50 m would typically be called “medium head”. Above 50 m would be classed as “high
head”.
The Flow Rate (Q) in the river is the volume of water passing per second, measured in
m3/sec. For small schemes, the flow rate may also be expressed in litres/second where 1000
litres/sec is equal to 1 m3/sec.
FIGURE 9: HYDROPOWER BASICS-HEAD & FLOW
Energy is an amount of work done, or the ability to do work, measured in Joules.
Electricity is a form of energy, but is generally expressed in its own units of kilowatt-hours
(kWh) where 1 kWh = 3,600,000 Joules and is the electricity supplied by 1 kW working
for 1 hour.
Power is the energy converted per second, i.e. the rate of work being done, measured in
watts (where 1 watt = 1 Joule/sec. and 1 kilowatt = 1000 watts).
Hydro-turbines convert water pressure into mechanical shaft power, which can be used to
drive an electricity generator, or other machinery. The power available is proportional to
the product of head and flow rate. The general formula for any hydro system’s power
output is:
P = h r g Q H

58
Where:
P is the mechanical power produced at the turbine shaft (Watts).
h is the hydraulic efficiency of the turbine.
r is the density of water (1000 kg/m3).
g is the acceleration due to gravity (9.81 m/s2).
Q is the volume flow rate passing through the turbine (m3/s).
H is the effective pressure head of water across the turbine (m).
The best turbines can have hydraulic efficiencies in the range 80 to over 90% (higher than
all other prime movers), although this will reduce with size. Micro-hydro systems
(<100kW) tend to be 60 to 80% efficient.
If we take 70% as a typical water-to-wire efficiency for the whole system, then the above
equation simplifies to:
P (kW) = 7 ´ Q (m3/s) ´ H (m)
The main figure illustrates a typical small hydro scheme on a medium or high head. Click
on the picture for a dynamic presentation of the elements of the scheme. The scheme can be
summarised as follows:
Water is taken from the river by diverting it through an intake at a weir.
In medium or high-head installations water may first be carried horizontally to the forebay
tank by a small canal or ‘leat’.
Before descending to the turbine, the water passes through a settling tank or ‘forebay’ in
which the water is slowed down sufficiently for suspended particles to settle out.
The forebay is usually protected by a rack of metal bars (a trash rack) which filters out water-
borne debris.
A pressure pipe, or ‘penstock’, conveys the water from the forebay to the turbine, which is
enclosed in the powerhouse together with the generator and control equipment.
After leaving the turbine, the water discharges down a ‘tailrace’ canal back into the river.

59
FIGURE 10: HYDRO-SCHEME COMPONENTS
In practice, sites that are suitable for small-scale hydro schemes vary greatly. They include
mountainous locations where there are fast-flowing mountain streams and lowland areas
with wide rivers. In some cases development would involve the refurbishment of a historic
water power site. In others it would require an entirely new construction. This section
illustrates the four most common layouts for a mini-hydro scheme.
A variation on the canal-and-penstock layout for medium and high-head schemes (Section
2.3) is to use only a penstock, and omit the use of a canal. This would be applicable where
the terrain would make canal construction difficult, or in an environmentally-sensitive
location where the scheme needs to be hidden and a buried penstock is the only acceptable
solution.
For low head schemes, there are two typical layouts. Where the project is a redevelopment
of an old scheme, there will often be a canal still in existence drawing water to an old
powerhouse or watermill. It may make sense to re-use this canal, although in some cases
this may have been sized for a lower flow than would be cost-effective for a new scheme.
In this case, a barrage development may be possible on the same site.
With a barrage development, the turbine(s) are constructed as part of the weir or immediately
adjacent to it, so that almost no approach canal or pipe-work is required.

60
Canal and Penstock: Penstock:
Mill Leat: Barrage:
FIGURE 11: HYDROPOWER BASICS-DIFFERENT SITE LAYOUTS
3.4.1 The benefits of hydro systems:
• Cut your electricity bills
A hydro system can generate 24 hours a day, often generating all the electricity you
need and more.
• Be paid to generate energy
If eligible, you'll get payments from the Feed In Tariff for all the electricity you
generate, as well as for any surplus electricity you sell back to the grid.
• Cheap heating and hot water
a hydro system may generate more electricity than you need for lighting your home and

61
powering your electrical appliances – so you can use the excess to heat your home and
your hot water too.
• A cheaper option for off-grid homes
installing a hydro system can be expensive, but in many cases it's less than the cost of
getting a connection to the National Grid if you don’t already have one.
• Cut your carbon footprint
Hydroelectricity is green, renewable energy and doesn't release any harmful carbon
dioxide or other pollutants.
3.4.2 Will hydropower work for us? :
Hydropower is very site specific. Most homes will not have access to a suitable resource
even if they have a water course running nearby. Assessing a hydro site properly is a job for
a professional. If you think you might have a suitable site the next step is to contact a
certificated installer, who will have a look at your site for you.
To be suitable for electricity generation, a river needs to have a combination of
Flow – how much water is flowing down the river per second, and
Head – a difference in height over a reasonably short distance
You could have either lots of flow and not much head (such as a river flowing over a weir)
or lots of head and not much flow (such as a mountain stream).
It’s also important to consider what happens to the river in summer. The minimum flow
during dry periods is usually the deciding factor, no matter how impressive the river looks
when it is in flood. If there is a good hydro resource in or near your community it might be
worth developing it as a community energy project, rather than as a system to supply just
one home. If you don’t think a hydro system is suitable for your home, use our Renewable
Selector to look at other options.
3.4.3 off grid:
Is your home connected to the National Grid? If not, hydro schemes are one of the most
reliable alternatives to mains supply for isolated properties, and can sometimes be cheaper
to install than a new mains connection.

62
3.4.4 Costs, savings and earnings:
Costs:
Costs for installing a hydro system vary a lot, depending on the location and the amount of
electricity you can generate. A typical 5kW scheme suitable for an average home might cost
from £25,000 including installation. Some sites cost less than this to develop; others cost
much more due to the nature of the site and the equipment used.
Maintenance costs vary but are usually low as hydro systems are very reliable.
Savings and income:
Savings will depend on the number of hours the turbine is able to run in a year, which in
turn will depend on how often the level of the river is high enough to supply the system.
Your installer will be able to predict this for you and estimate the amount of electricity that
will be generated. Hydro is eligible for Feed-in Tariffs and you will earn a tariff for each
kWh of electricity generated by your system. You will also receive another tariff for each
kWh of electricity.
Making the most of hydroelectricity:
To make the electricity you produce go further:
Use low energy bulbs throughout your home - these produce the same amount of light as
conventional bulbs and
Use up to 80% less electricity invests in energy-efficient appliances.
If you can reduce your energy demand so much that you don’t use all the electricity you
generate:
You can sell the surplus back to the grid, if you're connected, to earn extra money
You can store some of the surplus in batteries to use later if you're off grid.
Maintenance:
Once installed, most systems can last for 40 to 50 years, with low running and maintenance
costs and could last for longer if well maintained. There is the potential for the risk of
damage by debris carried downstream at times of flood but screening of the intake should
minimise this risk.

63
CHAPTER: 4
INNOVATION IN RENEWABLE ENERGY SOURSES

64
4.1 Energy Conservation According to Non-Conventional Sources:
Energy resources which are considered for large scale use after 1973 oil crisis are called
non-conventional energy sources. Non-conventional energy technologies are presently
under development or commercialization. Non conventional energy resources are likely to
cover more and more share of energy market in coming decades. e.g., wind, solar,
geothermal, ocean waves, ocean tide, bio-mass fuels, bio-gas, nuclear fusion fuels, fuel cells,
synthetic gases, fire wood.
4.2 Magenn Air Rotor Systems (MARS):
The Magenn Air Rotor System (MARS) is the next generation of wind turbines with cost
and performance advantages over existing systems. MARS is a lighter-than-air tethered
wind turbine that rotates about a horizontal axis in response to wind, generating electrical
energy. This electrical energy is transferred down the tether for consumption, or to a set of
batteries or the power grid. Helium sustains the Magenn Air Rotor System, which ascends
to an altitude as selected by the operator for the best winds. Its rotation also generates the
“Magnus” effect. This aerodynamic phenomenon provides additional lift, keeps the MARS
device stabilized, positions MARS within a very controlled and restricted location, and
finally, causes MARS to pull up overhead to maximize altitude rather than drift downwind
on its tether. It’s become mandatory rather than option to go for the renewable source of
energy today in the whole world. For the same requirements we need advance options for
future, hence MARS proves its excellence to use for better future.
In the fast growing world of technology & science, renewable source of energy is one of the
most crucial parts that can be used effectively for gaining energy. The use of various
renewable courses like wind, solar energy, and tidal energy can prove boon to mankind. In
present paper the use of wind energy for generation of energy by using suitable eco-friendly
technique is done.
4.2.1 Construction and Working:
MARS is a lighter-than-air tethered wind turbine that rotates about a horizontal axis in
response to wind, generating electrical energy. This electrical energy is transferred down the
tether for consumption, or to a set of batteries or the power grid. Helium sustains the Magenn
Air Rotor System, which ascends to an altitude as selected by the operator for the best winds.
Its rotation also generates the “Magnus” effect. As shown in Fig.2. This aerodynamic
phenomenon provides additional lift, keeps the MARS device stabilized, positions MARS
within a very controlled and restricted location, and finally, causes MARS to pull up
overhead to maximize altitude rather than drift downwind on its tether.

65
FIGURE 12: WORKING OF MAGENN AIR ROTOR SYSTEM

66
Construction of the Magenn Air Rotor System (MARS) is as shown in the Fig. It has
following
Important parts:
1) Aluminium tube: - Which is used for to restrict air flow, and gives thrust for the rotor to
rotate in the direction as shown in the figure. Here it converts the actual linear motion of
wind flow energy into rotary motion, which is necessary to rotate the generator shaft.
2) Cylindrical Balloon: - It is the balloon which is cylindrical shape and is filled with helium
air which is lighter than air, hence it could be placed above 300m height, where as
conventional windmills could be maximum 125m height.
3) Wind vane stabilizer: - It is one of the important parts of MARS. It restricts the MARS in
horizontal direction, and gives stability to the balloon.
4) Axle: It acts as a frame of MARS which is a single shaft connecting balloon, and
aluminium tube to the generator shaft, hence it is the power transferring element of the
MARS.
FIGURE 13: END PLATE WITH 5 KW GENERATOR ATTACHED TO ONE
SIDE

67
4.2.2 MARS Target Markets include:
1) Off grid for cottages and remote uses such as cell towers and exploration equipment.
2) Developing nations where infrastructure is limited or nonexistent.
3) Rapid deployment (to include airdrop) to disaster areas for power to emergency and
medical equipment, water pumps, and relief efforts (ex. Katrina, Tsunami) and military
applications.
4) Military applications.

68
4.2.3 Advantages of MARS over Conventional Wind Turbines:
1) Low cost electricity - under 10 cents per kWh.
2) Bird and bat friendly.
3) Lower noise.
4) Wide range of wind speeds - 2 to more than 28 meters/second.
5) Higher altitudes - from 200 to 800 feet above ground level are possible without expensive
towers or cranes.
6) Mobile.
7) Ideal for off grid applications or where power is not reliable.
Magenn Power
Product Model 10kW
Rated Power 10,000 Watts
Size (Diameter x
Length)
30 feet by 60 feet
Shipping Weight Under 3,000 lbs - depending on tether length
Volume of
Helium
33,000 cubic feet (approx.)
Tether Height 400 ft standard - up to 1,000 ft optional tether
length, in increments of 100 feet
Start-up Wind
Speed
2.0 m/sec - 4.48 mph
Cut-in Wind
Speed
3.0 m/sec - 6.7 mph
Rated Wind
Speed
12.0 m/sec - 26.8 mph
Cut-out Wind
Speed
25.0 m/sec - 53.7 mph
Maximum Wind
Speed
28.0 m/sec - 62.6 mph

69
Temperature
Range
-40ºC /-40ºF to +45ºC/+113ºF
Generators 2 x 5 kW
Output Form Various Options Available: 120 VAC 60Hz - 240
VAC 50 Hz - Regulated DC 12-600V
Warranty Up to 5 Years
Life Cycle 10 - 15 Years
Price (USD)
(Estimated)
TBD
Availability 2009-10
Table 4: Specification of MARS
4.2.4 CONCLUSION:
After realizing is various advantages like mobility, high performance characteristics, low
cost electricity, bird and environment friendly, lower noise and various other which are
discussed before we could conclude that the MARS is the most convenient, reliable,
renewable , safe and efficient way to generate power at almost all possible environmental
conditions in the world.

70
4.3 OSMOTIC POWER – a new Renewable Energy Source:
During the past decade, global climate change challenges and the world’s steadily growing
demand for energy have brought the need for more renewable energy to the top of the
international community’s agenda. Therefore, the United Nations decided at the first World.
Summit on Sustainable Development to create a specific forum dedicated to further advance
the deployment of renewable energy sources: the International Conference for Renewable
Energies. At the forum’s first meeting, all countries reaffirmed their commitment “to
substantially increase with a sense of urgency the global share of renewable energy in the
total energy supply.” During a follow-up meeting in 2008, it was clearly stated that in order
to reach this goal, it is imperative to use both existing and new renewable energy sources.
Based on more than a hundred years of experience in developing and operating hydropower, the
Norwegian utility company Statkraft1) has set the course for corroborating its leading role in
renewable energy generation by investing in the quest of new renewable energy sources in
strategic areas. As a result the company is today the world leader in development of Osmotic
Power, and has made state of the art achievements during the last years.
The pressure on the environment caused by human activities and especially the climate change
challenges related to continuously increasing greenhouse gas emissions, calls for a thorough
research of alternatives. Since the Kyoto Protocol in 1997, efforts to reduce carbon emissions
have been intensified. Among others, the EU adopted an integrated energy and climate change
policy in December 2008, including ambitious targets for 2020. It aims at bringing Europe onto
a more sustainable energy track – towards a low-carbon future with an energy-efficient
economy, which will cut greenhouse gases emissions by 20%, reduce energy consumption by
20% through increased energy efficiency, and meet 20% of Europe’s energy needs from
renewable sources. Despite these globally shared efforts, fossil fuels will continue to remain the
most important source of energy in the decades ahead, as they are the world’s main source of
low-cost and broadly available energy. In addition, the global consumption of energy is growing,
so the need for more renewable energy will become even more pressing in addition to the need
to reduce our dependency on finite and carbon-intensive fossil fuels as an energy source. In this
context of climate and environmental challenges, R&D has a key role to play in finding new
solutions. From a company’s perspective, R&D is also about safeguarding business outlook and
shaping growth ambitions. This means that we need to improve existing technologies as well as
work on building new renewable energy solutions. Statkraft has been engaged in developing
new renewable energy technologies since the early 90’s. Based on the company’s history as a
major Norwegian power generator, our focus has been on harvesting the energy that is available
along the far-reaching Norwegian coastline. For more than a decade we have been working
internally and in close collaboration with R&D parties as well as universities in order to find
ways to produce renewable energy from the natural forces of the ocean.
4.3.1 The power of osmosis:

71
It has been known for centuries that mixing freshwater and seawater releases energy. For
example, a river flowing into the salty ocean is releasing large amounts of energy. The
challenge is to utilise this energy, since the energy which is released from the mixing of salt
and freshwater leads only to a very small increase of the local water temperature. During the
last few decades at least two concepts for converting this energy into electricity instead of
heat have been identified. One of these is Pressure Retarded Osmosis (PRO). Thanks to this
technology it may be possible to utilise the enormous potential of a new, renewable energy
source. This potential represents a worldwide electricity production of more than 1600 TWh
per year – equivalent to half the annual power generation in the European Union. For
Pressure Retarded Osmosis, also known as Osmotic Power, the released chemical energy is
transferred into pressure instead of heat. This was first pointed out by Professor Sidney Loeb
in the early 1970’s, when he designed the world’s first semi-permeable membrane for
desalination of saline water for production of drinking water based on reverse osmosis.
Statkraft has been engaged in the research and development of Osmotic Power and related
enabling technologies since 1997. Together with its international R&D partners, Statkraft is
the main active and most progressive technology developer globally and therefore an
Osmotic Power knowledge hub. The team has made state-of-the-art achievements in terms
of developing a new energy efficient membrane technology during the past years.
Osmotic Power is based on naturally occurring osmosis, triggered by Nature’s drive to
establish equilibrium between different concentrations in liquids. Osmosis is a process by
which solvent molecules pass through a semi-permeable membrane from a dilute solution
into a more concentrated solution as illustrated in Figure.
FIGURE 14: PRESSURE-RETARDED OSMOSIS
The difference in concentration of salt between seawater and freshwater creates a strong
force towards mixing. The effects of this strong force to mix can be intensified through a
special membrane which separates salt and freshwater in a finite space and which only lets
the water pass through the membrane, while the salt ions are rejected. In this way, an osmotic
pressure can be achieved by the amount of freshwater moving to the seawater side. This

72
pressure can be in the range of 24 to 26 bars depending on the salt concentration of seawater.
More precisely, in a PRO system filtered freshwater and seawater are led into a closed
system as illustrated in Figure. Before entering the membrane modules, the seawater is
pressurised to about half the osmotic pressure, approximately 12-14 bars. In the module
freshwater migrates through the membrane into the pressurised seawater. This results in an
excess of diluted and pressurised seawater which is then split into two streams. One third of
this pressurised seawater is used for power generation in a hydropower turbine, and the
remaining part passes through a pressure exchanger in order to pressurise the incoming
seawater. The outlet from such a plant will mainly be diluted seawater (brackish water) that
will be led either back to the river mouth or into the sea.
FIGURE 15: OSMOTIC-BLOCK DIAGRAM
Consequently, the higher the salinity gradient between fresh- and saltwater, the more
pressure will build up in the system. Similarly, the more water that enters the system, the
more power can be produced. At the same time, it is important that the freshwater and
seawater is as clean as possible. Substances in the water may get captured within the
membrane’s support structure or on the membrane surfaces, reducing the flow through the
membrane and causing a reduction in power output and overall system efficiency. This

73
phenomenon, commonly known as fouling, is linked to the design of the system, to the
characteristics of the membrane, to the membrane module, and to the pre-treatment of the
fresh water and the sea water.
An Osmotic Power plant will to a large degree be designed of existing “off-the-shelf”
technology. The key components are the membranes, the membrane modules, and the
pressure exchangers and the lion’s share of efforts to commercialize Osmotic Power is
dedicated to improving and scaling up these components.
4.3.2 CONCLUSION:
Statkraft are convinced that Osmotic Power will develop into a new, renewable source of
energy, well capable of competing on the energy market of the future. Once again, in
memory of Professor Sidney Loeb, we would like to express our gratitude to and admiration
of his vision at a very early stage, his persistence, his ingenuity, and his valuable contribution
to solve one of the major challenges humanity is faced with:
“Establishing a Sustainable World for Coming Generations”

74
REFERENCES
• 1. “The 8051 Microcontroller and Embedded systems” by Muhammad Ali Mazidi
and Janice Gillispie Mazidi , Pearson Education.

75
• 2. ATMEL 89S52 Data Sheets.
• www.howstuffworks.com
• “Basics of Wind power generation”- by Amelia Earhart, Oxford University Press,
Athens
• Airborne Wind Energy Generation Systems
• Israel Patent Application 42658 of July 3, 1973. (see also US patent 3,906,250
granted September 16, 1975. Erroneously shows Israel priority)
• http://www.seas.ucla.edu/~sechurl/CP/sld001.htm
• http://www.statkraft.com/energy-sources/osmotic-power/

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