Consolidated Report on the Activities and Achievements Indo ...
Transcript of Consolidated Report on the Activities and Achievements Indo ...
Consolidated Report on the Activities and Achievements
Power Plant Optimization Component
Indo- German Energy Programme (IGEN) Phase-II
(2009-2015)
Ministry of PowerGovernment of India
Implemented by
Consolidated Report on the Activities and Achievements
Power Plant Optimization Component
Indo- German Energy Programme (IGEN) Phase-II
(2009-2015)
FOREWORD
In order to achieve the goal of the Government of India to make power available to all at
affordable price it is necessary to enhance efficiency in generation, transmission and
distribution of the electricity apart from promoting demand side management of electricity
conservation.
GIZ Germany and Central Electricity Authority (CEA) are implementing Indo-German Energy
Programme (IGEN) with the objective of improving efficiency of coal-fired generation in the
country and has taken up various activities in this direction such as providing Ebsilon
diagnostic software to 15 power utilities, training their engineers for using this software for
analysing and improving the performance of their thermal units effectively, demonstration of
energy savings achieved by implementing measures identified through mapping of
operating units and capacity building of power utility engineers by conducting study cum
familiarisation tour to Germany for sharing the best O&M practices being followed in Thermal
generation and state of the art technology used in German plants.
It is very heartening to know that the outcome of these activities has not only resulted in
energy /fuel saving but also helped in reducing CO2 emissions from the power sector. The
best part is that the plant engineers are now feeling more confident about their
understanding of gaps in performance of their stations and also have adequate knowledge
to take up appropriate measures to enhance efficiency of plant.
A brief report covering activities and achievements of IGEN programme, has been brought
out in the form of this book with an aim of dissemination of knowledge and experience
gained during the course of the implementation of this programme by the engineers of power
utilities.
I appreciate the efforts of the CEA and GIZ engineers for summarising entire activities of
IGEN in this book which would provide valuable information to various utilities and to
stakeholders in power sector.
New Delhi Major Singh
June 2015 Chairperson
Major Singh Chairperson
Central Electricity Authority
FOREWORD
India has been growing at a very fast pace of industrialization. This demands additional electricity - more than 1 GW of power generation capacity is currently being added every month. Out of this capacity, coal still rules as the largest contributor. However, just capacity addition cannot be the solution in the long run as resources and emission budgets are limited. One answer to this challenge is the increased energy efficiency by which fuel and emissions can be reduced significantly.
Therefore one focus of the Indo-German Energy Programme (IGEN) was on the generation side, especially on coal fired power plants. All the activities were jointly implemented with the Central Electricity Authority. Aim was to reduce fuel and emissions, based on trainings for plant engineers, knowledge exchanges and dissemination of software tools as well as continuous consultancies.
It gives me immense pleasure to value the high success of this programme. Savings of 1.2 Million tons of coal and 1.6 Million tons of CO2 each year are remarkable and more than expected. For me most important is that the plant engineers became self-sufficient in the analysis of gaps as well as in the identification and implementation of saving measures. Therefore I have full confidence that the huge savings will remain also in future. This consolidated summary report takes us to the beginning of our activities, reflecting the efforts which the IGEN team along with CEA and the consultant STEAG has taken the last six years and whom I thank a lot for their efforts. I like to share these experiences and wish you a good time with reading.
New Delhi Dr. Winfried Damm June 2015 Director
Dr. Winfried Damm Director
Indo-German Energy Programme
GIZ-India
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Contents
Executive Summary ............................................................................................................................................. 1
1. Introduction................................................................................................................................................... 3
1.1. Indian Power Sector ........................................................................................................................... 3
1.2. Low Carbon Growth Strategy for Generation Planning in India .................................................. 5
2. Indo-German Energy Programme (IGEN) ............................................................................................... 6
3. Training and capacity development of plants engineers with diagnostic software and study tours 7
3.1. Training of 101 engineers with adequate supply of diagnostic tool, Ebsilon® Professional ... 7
3.2. Human Resource Development to improve knowledge on critical areas................................... 8
4. Feasibility studies to identify savings measures for 17 plant units with the support of consultant
“case studies” ....................................................................................................................................................... 9
4.1. Findings of case Study .................................................................................................................... 10
4.2. Reasons for high operating gross heat rates ............................................................................... 11
4.3. Recommendations as proposed in the Case Studies ................................................................. 12
4.4. Impact of Case Studies ................................................................................................................... 12
5. Feasibility studies to identify savings measures for 30 further plant units “mapping reports” ....... 14
5.1. Findings of Mapping Reports .......................................................................................................... 15
5.2. Reasons for high operating gross heat rate ................................................................................. 16
5.3. Recommendations for Improving Energy Efficiency ................................................................... 19
5.4. Impact of Mapping Reports ............................................................................................................. 19
6. Implementation of exemplary saving measures in three selected plants (Model Power Plants) .. 21
6.1. Approach ........................................................................................................................................... 21
6.2. Identified gaps in Energy Efficiency area ...................................................................................... 21
5.3. Measures Recommended ............................................................................................................... 23
5.4. Conclusion and Findings ................................................................................................................. 24
7. Implementation of a demonstration boiler performance optimization system (BPOS) ............... 25
7.1. Approach ........................................................................................................................................... 25
7.2. BPOS System Description .............................................................................................................. 25
7.3. Conclusion and Benefits .................................................................................................................. 27
Abbreviations ...................................................................................................................................................... 30
Annexures ........................................................................................................................................................... 31
Annexure 1: 85 Units Mapped under IGEN Phase I ................................................................................ 31
Annexure 2: Formulae and Calculations .................................................................................................... 33
References .......................................................................................................................................................... 33
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Executive Summary
As per the growing energy demand of electricity in India, the generation has to be in kept at
same pace. This tremendous pressure urges for efficient electricity generation techniques.
Under Power Plant optimization Component, IGEN Phase-II, an average improvement in
heat rate of 3.5% was achieved for 27 units with a total capacity of 6.6 GW.. This refers to an
efficiency improvement of 1.2 % points and a CO2 emission reduction of 1.6 million tonnes
per year.
This was done with the training of 101 engineers on the use of Ebsilon® Professional
software and supply of 40 licenses to them. These trainings and distributions were catered to
15 thermal generating utilities.
Ebsilon® Professional is a diagnostic tool that helps the power plant operators to identify the
deviation of parameters against their design values. Ebsilon® Professional also helps to
undertake the “what if” scenarios of the thermodynamically cycle. Distribution of the software
was also accompanied with dedicated trainings and handholding exercise on use of same.
Utilities prepared 17 case studies, with the support of consultant and 30 mapping reports, by
their own, with the use of Ebsilon® Professional.
Apart from these four plants were identified for implementation of prioritised
recommendations to develop them as showcased model power plants. One of the units was
equipped with state of the art Boiler Performance Optimization System (BPOS).
All these activities resulted in a significant savings which has been discussed in various
chapters in the report. The summaries of quantified savings for each activity are shown in
the table and chart below.
S.No.
Activity Name Capacity
Improvement in Heat Rate from operating (%)
Improvement in Efficiency from operating (% points)
Coal Savings (kt/year)
CO2
Savings (kt/ year)
Monetary Savings (Cr. Rs/ year)
Monetary Savings (Million Euro/ year)
1 Impact of case studies (8 units) 1925 3.7 1.2 378 506 151 21.6
2 Impact of mapping reports (15 units) 3470 3.8 1.3 706 945 282 40.4
3 Impact of model power plants and BPOS (4 units)
1170 2.2 0.7 122 180 49 7.0
Total 6565 3.5%
(Weighted Average)
1.2 % (Weighted Average)
1206 1631 483 68.9
From the table above, it can be observed that the activities on coal fired power plants under
IGEN Phase-II resulted in an increase in average efficiency by 1.2 % points. This is
equivalent to a savings of 1.6 million tonnes of CO2 per year or 1.2 tonnes of coal per year. It
means an annual savings of 483 crore INR or 68.9 million Euro.
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Breakdown of annual 1.6 Million tons of CO2 savings in coal fired power plants with a capacity of 6.8 Gigawatt and an annual electricity production of 47000 GWh
The plants have become more prepared with the tool and knowledge to identify deviations in
operating conditions. It was also reported that some of the utilities are also practicing sharing
of knowledge from IGEN activities among other plants in their utility. This is creating a
cascading effect which was the long term objective of IGEN.
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0
50000
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1940 1960 1980 2000 2020Year
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city (
MW
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0100200300400500600700800900
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1940 1960 1980 2000 2020Year
Per
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(kW
h)
1. Introduction
1.1. Indian Power Sector
India is the fourth largest producer of electricity (European Union included) in the world. Since independence, there has been a significant capacity addition in every decade. However, since the last decade the capacity addition has increased colossally. This change can be attributed to the privatization of licensing policy of Indian power sector. The capacity addition to Indian power sector has been more than 196 times since independence, 1947.
Figure 1: Installed capacity in the Indian power sector
The per capita power consumption of India has also increased from a mere 16.3 kWh to 957 kWh (2013-14) since independence. This is a growth of over 58 times since then. On one hand where the Indian power sector is ageing with its coal based capacities, on the other hand it is quite young at the non-conventional generating sources. The growing demand of electricity is placing tremendous pressure on the power sector and coal being the largest in terms of capacity, also shares the largest segment of this burden. The demand for electricity is likely to continue to grow by about 8-9% per year to keep the pace of economic development in line with Government of India’s targets. The government has already announced its commitment to uninterrupted 24x7 hours electricity supply to consumers.
Figure 2: Per capita electricity consumption
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The power sector in India has witnessed drastic changes in the past few decades. The Electricity Act, 2003 paved way for the advent of reforms and competition in the power sector. The competition in power sector has brought “energy efficiency” at the central stage in supply and demand side management of power. India’s national and international commitment concerning environment is another important driver for energy efficiency in power generation. The power industry in India has registered significant progress since the inception of the economic planning process in 1951. Installed capacity grew from about 1362 MW in 1947 to about 2, 67,637 MW by 31st March, 2015, including over 31,692 MW (11.84 %) from renewables. The installed capacity as on 31-03-2015 is given in table below.
Table 1: Installed capacity as on 31.03.2015 (Figures in MW)
It is observant from the table above that out of 267 GW installed capacity; thermal alone is responsible for approximately 70% share. Also, of this 70%, coal based thermal power plants alone contributes 87 %. The share of each generating source towards Indian power sector is shown in figure below.
From the above figure it is evident that the coal shares the largest chunk of 60% followed by hydro 15%, renewable energy sources (R.E.S.)12%, gas based plants 8%, and the remaining is shared by diesel and nuclear. Though in past, Coal Plants were the major area of interest, now the renewable energy sources are gaining much popularity due to low CO2 approach. It has hence, become necessary for the existing Coal based Power Plants to reduce CO2 emission by enhancing efficiency. This is also backed by the PAT scheme of Govt. of India which mandates all power plants to reduce their heat rate or in other words increase efficiency by a target.
61.51% 8.62%
0.45%
2.16%
15.42%
11.84%
Coal
Gas
Diesel
Nuclear
Hydro
RES
Sector Hydro Thermal Nuclear R.E.S
Grand
Total
Coal Gas Diesel Total
State 11091.43 48130.00 7519.73 0.00 55649.73 5780.00 0.00 72521.16
Private 27482.00 58100.50 6974.42 602.61 65677.53 0.00 3803.67 96963.20
Central 2694.00 58405.38 8568.00 597.14 67570.52 0.00 27888.47 98152.99
Total 41267.43 164635.88 23062.15 1199.75 188897.78 5780.00 31692.14 267637.35
% 15.42 61.51 8.62 0.45 70.58 2.16 11.84 100
Figure 3: Contribution of generation sources towards total capacity
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52%
10%
5%
2%
10%
9%
12%
0% 0% Electricity
Transport
Residential
Other Energy Activities
Cement
iron and Steel
Other manufacturing Industries
Agriculture
Waste
1.2. Low Carbon Growth Strategy for Generation Planning in India
India is one of the lowest emitters of greenhouse gases (GHGs) in the world on per capita
basis. The per capita CO2 emission of India is 1.4 tCO2, which is less than one third of the
world’s average of 4.5 tCO2. Towards providing cleaner fuel and superior technology, and to
reduce India’s dependence on coal, a low carbon growth strategy is being adopted by the
Government for generation capacity addition during 12th Plan (2012- 2017) and future
plans. Accordingly, the Plan takes into account the development of projects based on
renewable energy sources as well as other measures and technologies promoting
sustainable development of the country. Two of the important steps of this Sustainable
Integrated approach are Efficiency Improvement of existing stations and Energy
Conservation in generation and at consumer end. India has already projected the estimated
capacity addition by Solar to be 100GW and by wind energy to be 60GW by the year 2022.
India has also prepared a national action plan for climate change and said that it will reduce
the emission intensity of its GDP by 20 to 25 percent, over 2005 levels, by 2020.
Approximately 11 Million tons of Coal per annum can be saved by increase of 1% in
efficiency of thermal power plants. Since the fuel cost amounts to approximately 3/4th of the
total average production cost, even a marginal improvement in efficiency results into huge
amount of saving of money. Thus, twin benefits of energy efficiency are – cost effectiveness
and reduction in greenhouse gas emissions.
According to a survey, coal based power plants have the maximum stake in CO2 production
in India, followed by transport and others. It can be observed from the above figure that
electricity production alone shares more than 50% for total CO2 production. Hence,
improvement of efficiency of thermal power plants will create a huge impact.
.
Figure 4: Share of emission of CO2 from each Sector
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2. Indo-German Energy Programme (IGEN)
The Indo-German Energy Programme (IGEN) deals with various projects/ components in
conventional and non-conventional generation techniques, demand side and consumer side
energy efficiency, etc. The Indo-German technical cooperation in the field of Energy
Conservation commenced when the first Indo-German Energy Efficiency Project was
launched in May 1995 by the Energy Management Centre, a predecessor organization to
the Bureau of Energy Efficiency (BEE). With the success of the project and looking into the
need of promoting Energy Efficiency in the country, a full-fledged Indo-German Energy
Program (IGEN) was launched in October 2003. IGEN was launched in the context of
enactment of Energy Conservation Act 2001 and establishment of Bureau of Energy
Efficiency. Out of the two components – Energy Efficiency component and Power Plant
Optimization component, the later, being implemented by Central Electricity Authority (CEA)
and GIZ, aims at improvements in energy efficiency of power plants.
The 1st Indo-German Energy Programme was executed from 2006 to 2009. It aimed at
potential studies of thermal power generating units and performance optimization of thermal
power stations. Under this, GIZ provided support to CEA for creating data base of the older
thermal power plants in India. The scope of the work primarily covered the analysis of 85
coal fired power generating units using Ebsilon® Professional. (Ref. Annexure-1).
While analyzing the efficiency of conventional power plants, one has to remember that fuel
cost amounts to approximately 75% of the total average production costs. This fact clearly
highlights the necessity of operating the plant at optimum efficiency. Along with cost
effectiveness, the reduction in the emission of air pollutants is also required. The
degradation of the plant efficiency is a normal process, but a permanent challenge to
minimize the degradation by measuring performance parameters and taking the corrective
action through the O&M exists. The studies from IGEN Phase-I, reflected a saving potential
of coal to the tune of 6.92 million tonnes per year. As per Indian quality of coal, the savings
would lead to a CO2 emissions reduction up to 10 million tonnes per year. This reconfirmed
the possibility of huge potential in Green House Gas mitigation. Mapping exercise
introduced power plants to the versatility of Ebsilon® Professional as a diagnostic tool and
enabler for planning for Energy Efficiency measures in Thermal Power Plants.
To make the energy efficiency efforts sustainable in the long run, phase II (Power Plant
Component) was launched to build on the achievements of phase I. The power plant
optimization component aims at capacity development and exchange of best practices. The
result oriented parameters for PPOC Phase-II were,
a) Training and capacity development of plants engineers with diagnostic software
and study tours
b) Feasibility studies to identify savings measures in plant.
c) Implementation of exemplary saving measures in three selected plants
d) Implementation of a demonstration boiler performance optimization system (BPOS)
The list of activities was designed accordingly to achieve the above mentioned results.
Steag Energy Service, were appointed as the consultant for the technical support for plant
engineers. Adelphi consult GmbH, was appointed the consultant for the study cum
familiarization tour to Germany.
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3. Training and capacity development of plants engineers with diagnostic
software and study tours
The capacity development was divided in two activities namely, a) training of 101 engineers
with adequate supply of diagnostic tool, Ebsilon® Professional, and b) human resource
development to improve knowledge on critical areas. The objective was to make the plant
operators self-sustainable in analyzing the gaps in their plant. To assist this, the gap
analysis software, Ebsilon® Professional and trainings were given. Also, to make them more
aware on critical areas, a study cum familiarization tour was organized.
3.1. Training of 101 engineers with adequate supply of diagnostic tool, Ebsilon® Professional
A total of 101 participants were trained on the use of Ebsilon® Professional preceded by
distribution of 40 Ebsilon® Professional licenses. Among the trainees, 97 were from thermal
generating utilities and 4 from CEA. The resource personnel from Steag Energy Services for
each two week training consisted of 8 specialists from India and one expert from Germany.
These distribution and trainings were done in batches, under main programme and its
extension phase. The distribution of Ebsilon® Professional licenses were accompanied by
distribution of laptops as well. The utilities signed a memorandum of understanding with GIZ
in presence of CEA. The list of beneficiary utilities is given in the table below.
S.No. Utility Number of Licenses in PPOC Phase-II
Number of Licenses under PPOC extension
Total Number of Licenses
Number of Laptops
1 APGENCO 1 3 4 4
2 CSPGCL 1 2 3 3
3 DVC 1 2 3 3
4 GIPCL 1 0 1 1
5 GSECL 1 2 3 3
6 HPGCL 1 2 3 3
7 MPPGCL 1 2 3 3
8 MAHAGENCO 1 2 3 3
9 NLCL 1 2 3 3
10 OPGCL 1 0 1 1
11 PSPCL 1 2 3 3
12 RRVUNL 1 2 3 3
13 TANGEDCO 1 2 3 3
14 TVNL 1 0 1 1
15 UPRVUNL 1 2 3 3
TOTAL 40 40 Table 2: List of Beneficiaries of Ebsilon® Professional
The trainings were held for 2 weeks per batch in New Delhi. This was followed by special
handholding exercises to make plant specific models at each plant site. This helped the
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plant professional to map their unit and carry out the gap analysis themselves. Many plant
prepared operating models for various conditions which helped them to understand the
behaviour of system in a better way.
3.2. Human Resource Development to improve knowledge on critical areas
Under this subcomponent, two weeks study tour to Germany was conducted. The key
features were visit to eleven power plants, power plant equipment manufacturers, power
plant associates, think tanks and universities. The focus was modernization and retrofitting
of power plants, online and offline monitoring programs, coal blending technologies and best
operation and maintenance practices.
During all the tour, German experts shared their knowledge and expertise by presenting best
practice examples, case studies and state of art technologies to the delegation. Furthermore
the tour was useful for exchanging knowledge between the participants.
A total of 53 participants were divided into three batches. Each batch had a visit for two
weeks. The composite list consisted of 41 engineers from state thermal generating utilities,
seven representatives from Central Electricity Authority (CEA), and two representatives from
Ministry of Power (MoP) participated in the tours. Additionally, experts from GIZ also
attended the first study cum familiarization tour. The study tours were conducted in oct-2011,
and sept-oct-2011.
The two week training visits provided contacts to relevant institutions and companies for
further cooperation and to develop public private partnership initiatives. During the tour, the
participants visited different coal and lignite fired power plants, one gas fired power plant and
one geothermal power plant. The tour proved quite useful in dissemination of knowledge and
best practice exchange.
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4. Feasibility studies to identify savings measures for 17 plant units with
the support of consultant “case studies”
Case studies were primarily done by the plant with full onsite and offsite of consultant.
These studies were done on 17 units with capacities adding up to 3.6GW. These were the
base for implementation of energy efficiency measures. The monitoring on this activity for 8
units with a total of 1.9 GW capacities, revealed an efficiency improvement of 3.7 % (1.2%
points). This meant 0.5 million tonnes of CO2 emission savings per year or 0.38 million
tonnes of coal savings per year.
Model analysis was carried out to determine the degradation of performance of important
equipment which can affect the overall plant performance and efficiency. Enthalpy drop
values were obtained from the HS (Mollier) diagrams. The model enabled assessment of
impact of changes in some parameters over other parameters. Such changes included
deviations in coal quality as well. Deviations have been determined with the help of the
model taking into account the impact of external factors and current operating conditions of
the plant. Some of the important parameters analyzed are:
Turbine and Gross heat rate
Boiler efficiency & unit efficiency
Efficiency of turbines (HP, IP, LP)
Regenerative heater performance
Condenser performance
Excess O2
The list of units that undertook case study is mentioned below
Sl No State Board/ Electricity Gen. Company
Power Station Unit size MW
Unit No
1 APGENCO Kothagudem Thermal Power Plant 120 6
2 GSECL Sikka Thermal Power Plant 120 1
3 GIPCL Surat Lignite 125 3
4 OPGC IB Valley Thermal Power Plant 210 2
5 HPGCL Panipat Thermal Power Plant 210 6
6 MAHAGENCO Khaperkheda Thermal Power Plant 210 3
7 GSECL Gandhinagar Thermal Power Plant 210 5
8 GSECL Wankbori Thermal Power Plant 210 2
9 NLCL Neyveli lignite 210 2
10 NLCL Neyveli lignite 210 7
11 TANGEDCO Tuticorin Thermal Power Plant 210 2
12 TANGEDCO Tuticorin Thermal Power Plant 210 4
13 PSPCL GHTPP, Lehra Mohabbat TPS 210 1
14 TVNL Thenughat Thermal Power Plant 210 2
15 DVC Durgapur Thermal Power Station 210 4
16 RRVUNL Suratgarh Thermal Power Plant 250 3
17 UPRVUNL Anpara Thermal Power Plant 500 4
Total Capacity 3635 Table 3: list of units that prepared case study reports
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4.1. Findings of case Study
The studies revealed that most of the units are being operated under various constraints like
poor quality of coal, insufficient attention to proper maintenance of boiler, turbine and other
equipment, operating parameters different from the rated values and obsolete
instrumentation. These have resulted in high heat rates and unreliable plant operations. The
savings potential from these 17 case study reports have been listed in table below.
Parameters 120 MW (2)
125 MW (1)
210 MW (12)
250 MW (1)
500 MW (1)
Total (toe)
Short Term Potential ( 117365.47 toe)
MS pressure 361.30 0 3663.11 0 52.12 4076.53
MS Temp 34.44 0 1351.69 735.84 0 2121.97
RH Temp 319.35 0 2339.79 153.30 723.58 3536.02
Condenser Vacuum
691.69 1273.07
40922.94 3766.13 46653.83
UBC in Fly Ash 559.24 0 13521.06 0 14080.30
UBC in bottom ash
342.17 0 5430.96 333.43 298.94 6405.49
Makeup 0 0 15494.69 0 2057.29 17551.98
Excess air 2977.11 688.22 18547.02 0 727.01 22939.35
Long Term Potential (347881.32 toe)
RH Spray 0 515.21 5902.90 0 1282.20 7700.31
SH Spray 8.65 15.59 286.49 0 77.26 388.00
Exit Gas Temp 2472.42 1728.24
26512.61 0 3679.20 34392.47
Change in FW temp
1279.99 0 4008.67 0 5365.50 10654.17
HPT Efficiency 2305.49 3612.85
22362.29 4849.65 3633.21 36763.48
IPT Efficiency 3070.22 569.26 20195.44 617.19 5274.13 29726.24
LPT Efficiency 4160.73 0 163036.17
6169.10 17004.04 190370.04
HPH TTD 3116.58 0 18124.09 700.89 1926.06 23867.62
HPH DCA 0 5.73 1712.99 80.48 0 1799.20
LPH TTD 83.44 0 8963.30 938.20 253.86 10238.81
LPH DCA 0 0 631.95 0 1349.04 1980.99
Total 465246.78
Table 4: Savings Potential from 17 Case Study reports
It can be observed that from these 17 case study reports, a saving potential worth 0.46
million tonnes of oil equivalent was revealed. The calculations of indices were done
considering 70% PLF.
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4076.53 2121.97
3536.02
46653.83
14080.30
6405.49
17551.98
22939.35
Total Short term Saving Potential (117365.47 toe)
MS pressure (kg/cm2) MS Temp (ᴼC)
RH Temp (ᴼC) Condenser Vacuum (mmHg)
UBC in Fly Ash (%) UBC in bottom ash (%)
Makeup (%) Excess air (%)
7700.31 388.00
34392.47
10654.17
36763.48
29726.24 190370.04
23867.62
1799.20
10238.81 1980.99
Total Long term Saving potential (347881.32 toe)
RH Spray (t/h) SH Spray (t/h)
Exit Gas Temp (ᴼC) Change in FW temp (ᴼC)
HPT Efficiency (%) IPT Efficiency (%)
LPT Efficiency (%) HPH TTD (K)
HPH DCA (K) LPH TTD (K)
LPH DCA (K)
Capacity range of units (MW)
No. of units
Average Deviation of Boiler Efficiency (%)
Average Deviation of Turbine Heat Rate(%)
Average Deviation of Gross Heat Rate (%)
120 2 5.41 5.42 11.91
125 1 0.62 1.15 1.01
210 12 3.11 5.94 10
250 1 0.9 5.71 6.74
500 1 1.95 7.92 10.08
Table 5: Major variation (%) among important parameters from case Study reports
Table above shows the average deviation of TG Heat rate, Boiler Efficiency and Unit Heat
rate among various ranges of capacities.
The total saving potential for 17 units (3635MW) works out to be 465246.78 toe per year
(Short term117365.47 and long term 347881.32 toe per year) as shown in fig below.
Figure 5: Short term and Long Term Savings potential with Factors considering 70%PLF
On analysis of fig above, it is observed that the maximum contributing factor towards short
term savings is condenser vacuum and for long term savings is turbine efficiency. Other
major contributing factors are main steam (MS) temperature, unburnt carbon, and excess air
4.2. Reasons for high operating gross heat rates
Based on observations during site visit and discussions with the site engineers on the
operation and maintenance aspects of the power plants, some areas commonly observed to
be responsible for high operating gross heat rate are listed below. These observations are
not applicable to all the units but are representative of the type of problems encountered.
For specific sites, the individual reports may be referred.
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Analysis of observations for different power plants indicates that the major reasons for the
high operating gross heat rate are:
Un-optimized boiler combustion
Low turbine cylinder efficiency
Low condenser vacuum.
Heater performance
High air ingress in the boiler/air heater
Inefficient operation of air pre-heaters
High super heater and re-heater spray
Make Up flow
Coal quality not conforming to design coal
Inefficient soot blowing of the boiler tubes
4.3. Recommendations as proposed in the Case Studies
Recommendations to improve the performance and efficiency of the plant have been made
for each of the units covering maintenance and, operational aspects. These
recommendations take into account the observations at site, available information with
project engineers and deviations in operating parameters determined by Ebsilon®
Professional model. The recommendations have been divided into two categories namely:
Short term and Long Term
The short term recommendations are those which mostly relates to operating practices, can
be implemented immediately at lesser cost, permitting picking up of low hanging fruits.
The long term recommendations cover overhauling and retrofit in the plant. The
recommendations cover energy audit of air flue gas path, replacement of APH blocks,
providing oxygen analyser at APH outlet, steam path audit for turbines and checking the
blade profile, checking and rectification of heater baffle arrangement, burner management
system, auto controls, turbine, ESP controls and ID fan control improvement. These
recommendations, however, will need further detailed studies which could be taken up at the
stage of next annual overhauling or at the time of Residual Life Assessment studies.
4.4. Impact of Case Studies
The activities were aimed at development of self-reliability among the plant engineers to
identify gaps and bridge them. All together 17 thermal generating units prepared case
studies of their operating condition to find out the deviation from their design parameters.
Accordingly recommendations were also made on short and long term basis. This entire
activity was closely supported by the experts from Steag. The activity was designed till the
recommendation against the gaps identified and the implementation of measures were to be
done by the plant based on the recommendations. The plants did their part in the most
promising way they could. In the conclave held in Jan-2014, the plants presented their work
of implementation and other works with the use of Ebsilon® Professional. These works led
to a betterment of heat rate. Some of the plant even quantified their savings. The quantified
savings and their analysis on other parameters are shown in the table below.
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S.No.
Plant name Utility Name
Capacity
Improvement in Heat Rate from operating (%)
Improvement in Efficiency from operating (%)
Coal Savings (kt/year)
1 Suratgarh TPS RVUN 250 4.01 4.18 44.3
2 Tenughat TPS TVNL 210 6.45 6.90 69.7
3 Anpara TPS UPRVUNL 500 0.68 0.69 22.6
4 Surat Lignite TPS
GIPCL 125 1.10 1.11 9.1
5 Tuticorin TPS TANGEDCO
210 8.98 9.87 123.5
6 IB Valley TPS OPGC 210 2.19 2.24 26.2
7 Gandhinagar TPS
GSECL 210 4.33 4.52 38.3
8 Neyveli Lignite TPS
NLC 210 3.11 3.21 44.6
Table 6: Achievements of units that prepared case study reports
The above mentioned savings leads to a CO2 emission reduction of 0.5 million tonnes per
year with an equivalent monetary savings of 151 Crore INR. This is a huge savings and the
biggest achievement is that the plants have done this on their own part. It can also be said
that from a capacity of 1925 MW (sum of capacities mentioned in table above), a savings
worth 0.5 million tonnes of CO2 emission reduction was achieved.
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5. Feasibility studies to identify savings measures for 30 further plant
units “mapping reports”
The focus was to develop in house capabilities amongst identified thermal power plants to
use Ebsilon® Professional and undertake mapping exercise to plan for interventions needed
to restrict controllable losses. Power plant efficiency engineers were extensively trained in
application of Ebsilon® Professional and were provided handholding by consultant in the
entire process of the project leading to mapping of further 30 units. The methodology was
kept same as that in the case study reports. Where in the case study reports, it was more
with the stronger support of Steag Energy Services India, in Mapping Reports the emphasis
was on plant’s own efforts. The list of different size of units, state generating utility wise
mapped are shown in the table below
Sl No State Board/ Electricity Gen. Company
Power Station Unit size MW
Unit No
1. PSPCL Guru Nanak Dev Thermal Power Station 110 1
2. HPGCL Panipat Thermal Power Station 120* 1
3. GIPCL Surat Lignite Thermal Power Station 125 1
4. GIPCL Surat Lignite Thermal Power Station 125 4
5. DVC Mejia Thermal Power Station 210 3
6. GSECL Gandhinagar Thermal Power Station 210 4
7. HPGCL Panipat Thermal Power Station 210 6
8. NLCL Neyveli Second Thermal Power Station 210 4
9. NLCL Neyveli Second Thermal Power Station 210 6
10. OPGC IB Thermal Power Station 210 1
11. MPPGCL Sanjay Gandhi Thermal Power Station 210 4
12. TVNL Tenughat Thermal Power Station 210 1
13. MAHAGENCO Nasik Thermal Power Station 210 5
14. CSPGCL Hasdeo Thermal Power Station 210 1
15. TANGEDCO Tuticorin Thermal Power Station 210 3
16. TANGEDCO Tuticorin Thermal Power Station 210 5
17. TANGEDCO Mettur Thermal Power Station-1 210 4
18. DVC Chandrapura Thermal Power Station 250 7
19. DVC Chandrapura Thermal Power Station 250 8
20. MPPGCL Satpura Thermal Power Station 250 10
21. UPRVUNL Harduaganj Thermal Power Station 250 8
22. PSPCL Guru Hargobind Thermal Plant 250 3
23. MAHAGENCO New Parli Thermal Power Station 250 6
24. CSPGCL DSPM Thermal Power Station 250 2
25. RRVUNL Suratgarh Super Thermal Power Station 250 1
26. RRVUNL Suratgarh Super Thermal Power Station 250 4
27. UPRVUNL Anpara Thermal Power Station 500 5
28. DVC Durgapur Steel Thermal Power Station 500 1
29. DVC Mejia Thermal Power Station 500 7
30. APGENCO Vijayawada Thermal Power Station 500 7
Total MW of Units Mapped 7460
Table 7: Details of Units Mapped
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5.1. Findings of Mapping Reports The studies revealed that most of the units are being operated at differed conditions than
the design parameters. These were mainly due to poor quality of coal, insufficient attention
to proper maintenance of boiler, turbine and other equipment, operating parameters different
from the rated values and obsolete instrumentation. One major factor which was affecting
most of the units was the backing down due to grid restriction. The units are forced to run on
a lower loading due to restrictions from grid. These have resulted in high heat rates and
unreliable plant operations. The savings potential from these 30 mapping reports have been
listed in table below.
Parameters 110-120 MW
125 MW 210 MW
250 MW
500 MW
Total (toe/yr)
No. of units in category
2 2 13 9 4
Short Term Potential ( 380578 toe)
MS pressure 2350 46 20363 3242 73 26073
MS Temp 860 43 4420 5078 2707 13106
RH Temp 1767 398 5584 3568 2573 13890
Condenser Vacuum
8365 409 55394 53027 15395 132591
UBC in Fly Ash 6934 0 37675 8742 5212 58562
UBC in bottom ash
1943 0 34247 8927 2345 47462
Makeup 0 0 21375 21257 7197 49829
Excess air 543 5414 1221 11696 20191 39065
Long Term Potential ( 782140 toe)
RH Spray 0 324 7612 2992 733 11660
SH Spray 42 23 4299 234 730 5328
Exit Gas Temp 1018 1494 50802 19625 9829 82768
Change in FW temp
359 2183 9768 8313 7306 27930
HPT Efficiency 5433 0 131322 23050 50203 210007
IPT Efficiency 108 0 23632 37332 40998 102069
LPT Efficiency 0 12295 80653 24697 73817 191463
HPH TTD 2604 0 27693 15060 77348 122705
HPH DCA 0 0 2879 1040 2523 6442
LPH TTD 5416 0 8253 0 4054 17723
LPH DCA 0 0 221 0 270 491
Coal Moisture 0 1382 1446 726 3554
Total 1162718
Table 8: Savings potential from 30 Mapping Reports
It can be observed that from these 30 mapping reports, a saving potential worth 1.16 million
tonnes of oil equivalent was revealed. The calculations of indices were done considering
85% PLF.
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Capacity range of units (MW)
No. of units
Average Deviation of Boiler Efficiency(%)
Average Deviation of Turbine Heat Rate (%)
Average Deviation of Gross Heat Rate (%)
110-120 2 4.69 7.75 12.92
125 2 0.69 0.87 1.56
210 13 2.97 6.48 9.64
250 9 0.93 5.81 7
500 4 0.26 7.1 6.08
Table 9: Major variation (%) among important parameters from mapping reports
5.2. Reasons for high operating gross heat rate The heat rate improvement opportunities for existing units include reductions in heat rate
due to process optimization, more aggressive maintenance practice and equipment design
modifications. Opportunities exist in the boiler, turbine cycle and in the heat rejection
system. The overall level of heat rate improvement which can be achieved varies with unit
design, maintenance condition, operating conditions and type of coal.
Major reasons for the high operating gross heat rate are:
Load factor: The heat rate of a coal-fired power plant represents the amount of heat,
typically in kcal/kg, needed to generate 1 kilowatt-hour (kWh) of electricity. Accordingly,
typical units for heat rate are kcal/kWh. For a given power plant, heat rate depends on the
plant’s design, its operating conditions, and its level of electric power output. Loading factor
decides the upper limit of heat rate once the unit is in operation. For a selected design set of
parameters a unit gives power at different heat rates at different loads. The loading factor is
so important that a supercritical unit operating at 70 % loading factor will be no better than a
subcritical power plant operating at 100% loading factor.
In case of 30 units mapped, the average operating loading of 110-120 MW,125MW, 210
MW, 250 MW and 500 MW plants are 89.8%,100%, 94.48%, 98.67 % and 100%
respectively. Thus it is evident from the above that in the case of units mapped, the low load
factor was least responsible for deterioration in heat rate.
Boiler combustion optimization: The boiler is an important system to be looked for
improvement in heat rate. The operating conditions in a typical pulverized coal fired boiler
can be controlled by adjusting the fuel-air ratio, mixing patterns of coal, flow of combustion
air and adjustment of O2 level. Adjusting these parameters affects combustion efficiency,
steam temperatures, slagging and fouling patterns and furnace heat absorption, which in
many boilers in turn have significant effects on unit heat rate and emission level.
In case of 30 units mapped, the boiler efficiency ranged from 82 % to 86 %. Around 19.6 %
energy loss are accounted due to deteriorated boiler performance.
Sootblowing optimization: Slagging and fouling deposits on the heating surfaces strongly
affect heat absorption pattern in pressure parts, steam and flue gas temperature and unit
17 | P a g e
heat rate. Sootblowing optimization helps in improving the optimum sootblowing strategies
which prevent built up of soot and slag deposits and improve the heat rate.
In most of the mapped soot blowing is done on fixed periodicity and also LRSBs are not in
operation. Thus sootblowers should be used on need basis in every shift in furnace zone
and the LRSBs should be operated as required.
Degradation in Turbine Performance: The performance of turbine deteriorates over time
due to nozzle and blade erosion, seal leakage and periodic turbine outages. One of the
techniques used to prevent excessively high steam temperatures for HPT and IPT is to
spray water into the steam. Water for spray are taken from the turbine cycle and result in an
increase in heat rate. Consequently, attemperation spray flow rates should be the minimized
to the design limit to control steam temperatures.
Turbine efficiency is deteriorated a considerable amount compared to design, in respect of
units mapped around 43.3 % energy losses is attributable to this account.
Low condenser vacuum: As the steam temperature in the condenser increases above
design limit, the back pressure increases, which results in reduction in MW generation and
leads to increase in cycle and unit heat rate. Units where heat is rejected to river water,
condenser pressure can increase due to increase in river water temperature and/or
condenser fouling. Units having cooling towers, the back pressure can increase due to facts
such as condenser fouling, cooling tower performance deterioration, and increases in
ambient temperature and humidity.
In case of 30 units mapped, approximately 11.4 % losses are accounted from the deviation
of condenser vacuum.
Feedwater Heater performance: Thermal performance losses occur in feedwater heaters.
These controllable losses frequently occur because of poor performing level controls. The
problems can range from something as simple as inaccurate or fluctuating readings across
several instruments that leave the real level in question to those that justify taking a
feedwater heater out of service. Regardless of the severity, poor feedwater heater level
control effects overall boiler and turbine cycle efficiency (i.e. increase in unit or turbine cycle
heat rate). The higher the feedwater temperature, the lesser fuel is required to produce the
steam used to produce electricity in the steam turbine. However, steam is extracted from
different locations from the steam turbine for feedwater heating, which increases the plant
heat rate. The net effect of feedwater heating using extraction steam is a reduction in the
plant heat rate.
The energy loss calculated to be around 12.67 %, on account of feed heater performance of
30 units mapped.
Air heater Performance: Poorly maintained air heater degrades the heat rate. As a unit
ages, the percentage of air leaking past the seals increases, which lowers the plant
efficiency due to the increase of air flow sent through the FD fans to maintain sufficient O2
levels in the boiler. Worn-out/choked heating elements, improper seal clearances, damaged
sector plates and side sealing plates, air ingress due to damaged expansion bellows,
improper sealing of inspection holes results in the poor air preheater performance. Thus
18 | P a g e
increase in flue gas pressure drop, reducing the air heater leakage can decrease the plant
heat rate.
In case of 30 units mapped APH leakage varies from 4 % to 20 % and the energy loss due
to change in exit gas temperature is found to be 7.12%.
Makeup flow: Makeup is the quantity of water that is lost from the cycle during operation.
Losses bsetween 0% to 3% are normally acceptable for a cycle make up to offset cycle
losses which may be on account of various leakages in the system; boiler blow down, soot
blowing and valve passing. The additional make up flow result in higher feed water thermal
duties which causes additional extraction flows and higher pump duty requirement, in turn
increase the heat rate.
The heat rate deviation for make-up is an approximation, as the location in the cycle of each
loss is not known, therefore, the exact heat rate deviation is not known. The energy loss due
to make up water consumption works out to be 4.29 % in case of 30 units mapped.
High Moisture Coal and Reduced Stack Temperature: High moisture levels in coals have
several adverse impacts on the operation of a pulverized coal generating unit, for they can
result in fuel handling problems and they affect heat rate, stack emissions and maintenance
costs. By using the waste heat to reduce coal moisture before pulverizing the coal can
provide heat rate benefits. The degree to which performance improves depends strongly on
the degree of drying. Opportunities also exist to condense moisture from flue gas by
reducing flue gas exit temperature. Captured sensible and latent heat can be used to
improve unit heat rate through efficiency improvements both in the boiler and turbine cycle.
It is found that the moisture percentage is closer to design limit in almost all the plants, so
this factor cannot be attributed to energy loss in case of 30 units mapped.
Fig 6: Gap analysis for major heat loss areas
11%
20%
43%
13%
13% Condenser
Boiler
Turbine (HPT+IPT+LPT)
Heater
Minor losses
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Deterioration in turbine and heater performance, degradation in condenser vacuum and
boiler performance contributed major energy losses as shown in figure above. The minor
loss area consists of main steam and reheats parameters, make-up water, superheater and
reheater spray, and feedwater temperature. The analysis made in Figure 4.1 should be
taken as guiding factor while making investment/ expenditure planning for energy efficiency
interventions.
5.3. Recommendations for Improving Energy Efficiency
Since each plant has its own operational features and design parameters, recommendations
to improve the performance and energy efficiency of the plant have been made for each of
the units. The recommendations made cover maintenance and operational aspects. The
inputs for arriving at recommendations are (i) observations at site, (ii) available information
with project engineers including plant’s operation and maintenance history and (iii)
deviations in operating parameters determined by Ebsilon® Professional model depicting
component behavior with change in boundary conditions relating to important operation
parameters. The recommendations have been divided into two categories namely: Short
term and Long Term
The short term recommendations are those which mostly relate to operating practices and
minor maintenance intervention, can be implemented immediately at lesser cost, permitting
picking up of low hanging fruits. The long term recommendations are those which can be
implemented during overhaul/ forced outage etc. and would require higher quantity of
resources.
Emerging out from experience of mapping of 30 units, it can be concluded that instead of
following ad-hoc approach in energy efficiency in thermal power plants, adoption of Systems
Approach for Efficiency Management is the need of hour. It would call for focus on systems
& procedures for good Operation & Maintenance practices. The following need to be
institutionalized for continual improvement in energy efficiency:
Energy Efficiency Management System
Advanced tools, technologies & systems
Skill development and training
Documentation and guidelines & awareness program
Maintenance Management System
Outage Management and Planning system
IGEN Phase- II has provided opportunities to State Generating companies to attain
sustainability in application of analytical tools for planning and providing inputs and
interventions to minimize controllable losses in thermal power plants leading to achievement
of targeted energy efficiency level.
5.4. Impact of Mapping Reports
Similar to the case studies, 30 units also mapped their units as a part of IGEN activity and
prepared reports. The difference between the case study and the mapping reports are that
where the former was done with full support of consultant Steag, the later was done by the
plant on their own. The plants identified the gaps in their units and made recommendations
20 | P a g e
accordingly. They even implemented some of the measures they identified and achieved
savings. These savings quantified in terms of various decision parameters are mentioned in
the table below.
S.No.
Plant name Utility Name
Capacity
Improvement in Heat Rate from operating (%)
Improvement in Efficiency from operating (%)
Coal Savings (kt/year)
1 Chandrapura CTPS
DVC 250 3.98 4.14 49.6
2 Chandrapura CTPS
DVC 250 4.05 4.22 38.5
3 Korba HTPS west
CSPGCL 210 11.12 12.51 134.3
4 Korba DSPM TPS
CSPGCL 250 0.51 0.51 6.8
5 NLC NLC 210 0.71 0.72 12.3
6 NLC NLC 210 5.64 5.97 99.3
7 Tuticorin TANGEDCO
210 1.90 1.94 23.6
8 GHTP PSPCL 250 0.81 0.81 7.6
9 Anpara TPS UPRVUNL 500 4.75 4.99 139.1
10 IB Valley OPGCL 210 1.79 1.82 23.2
11 Gandhinagar TPS
GSECL 210 2.68 2.76 17.1
12 Satpura MPPGCL 250 5.35 5.65 64.3
13 SGTPS MPPGCL 210 5.31 5.61 63.2
14 Surat Lignite GIPCL 125 2.42 2.48 16.0
15 Surat Lignite GIPCL 125 1.38 1.40 11.4 Table 10: Achievements of units that prepared case study reports
The above mentioned savings leads to a CO2 emission reduction of 0.945 million tonnes per
year with an equivalent monetary savings of 282 Crore INR. This is a huge savings and the
biggest achievement is that the plants have done this on their own part. It can also be said
that from a capacity of 3470 MW (sum of capacities mentioned in table above), a savings
worth 0.945 million tonnes of CO2 emission reduction was achieved.
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6. Implementation of exemplary saving measures in three selected plants
(Model Power Plants)
To make the recommendations of case study and mapping reports viable and practical, the
Model Power plant activity was conceived. The aim of Model Power plant was to
demonstrate the recommendations by implementing the mainly short and medium term
measures. These measures basically consisted of better operation and maintenance
practices and energy efficiency measures. The activities of Model Power plant resulted in an
average efficiency increase of 2.7% (0.9% points). This means an annual savings of 0.18
million tonnes of CO2 or 0.12 million tonnes of coal. This analysis was done from 3 units with
a total capacity of 920 MW.
Moving forward with the concept, four thermal power units were identified in close steering
with CEA, for model power plant activity. These were:
1) Bhusawal TPS, Unit #3, 210 MW
2) Mettur TPS, Unit#1, 210 MW
3) Durgapur Steel TPS, Unit 1, 500MW
4) Giral Lignite TPS, Unit#1, 125 MW
6.1. Approach
Steps taken to identify energy efficiency improvements areas and measures and
quantifiable energy saving on account of implementation of select recommendations
Gap identification and analysis based on:
Assessment of unit based on data/documents collected from the plant, hot walk
down survey and comparing different conditions or modes of operation
Assessment of the impact of individual equipment performance’s variation on
overall plant working/performance.
Thermodynamic analysis of the unit with the help of Ebsilon® Professional
Identification of potential areas of improvement and detailing out recommended
measures for energy efficiency improvement.
Assistance to the plant in implementation of agreed energy efficiency measures.
6.2. Identified gaps in Energy Efficiency area Most of the gaps identified were somewhat common for all plants. Additionally, some plants
had their typical area of improvement. Some of gaps common to all plants are listed below:
Partial load operation: This was prevalent in almost all the plants. The units had to run on
lower loading due to external reasons, mainly restriction from the grid. However, at some
plants, it was also due to their internal factors like low vacuum, unavailability of fuel, etc..
This affects the heat rate significantly.
Coal: In most of the plants the availability and quality of coal is the biggest issue. The
designed coal is not available and the coal sourced from other places doesn’t meet design
requirement. This not only leads to a higher heat rate but also deteriorates equipment in
22 | P a g e
long run. A higher ash content in coal leads to problem in ash handling system. Also, as the
availability of coal became a problem in near past, the coal sourced from other/ far sources
increased the generation cost.
Low Vacuum: This was mainly due to deposits in the condenser. Also the performance of
cooling tower was affecting this. At some plants the cooling water pump was also
responsible for low vacuum.
Air fans: The primary, secondary and induced draught fans were operating at their maximum
margins. This was due to many reasons, such as, leakages in the ducts, air preheater, high
ash content in coal (leading to high erosion in ID fan impeller and deterioration of
performance),
Boiler combustion: In almost all the plants, the problem of combustion appeared. The fuel-
air ratio, mixing patterns of coal, flow of combustion air and adjustment of O2 level, were not
optimum. This affected the combustion efficiency, steam temperatures, slagging and fouling
patterns and furnace heat absorption.
Unburnt Carbon: Due to improper combustion, poor milling performance, inadequate fuel air
ratio, coal quality, the unburnt in fly ash as well as bottom ash was on higher side. This
resulted in waste of energy ultimately leading to higher heat rate.
Soot blowing optimization: Deposits on the heating surfaces was found in the boiler. This
strongly affected heat absorption pattern and led to improper temperature distribution in
pressure parts, steam and flue gas temperature.
Air heater performance: Air leakages in seals were observed which lowers the plant
efficiency due to the increase of air flow sent through the FD fans to maintain sufficient O2
levels in the boiler. Worn-out/choked heating elements, soot deposit, improper seal
clearances, damaged sector plates and side sealing plates, air ingress due to damaged
expansion bellows, improper sealing of inspection holes were also observed.
Degradation in turbine performance: Deterioration of turbine performance and hence higher
heat rates were observed. While the exact influence on turbine can be determined when it is
opened, the inference from the operating parameters and the Ebsilon® Professional model,
was that there might be chances of nozzle/ blade erosion and seal leakages. The last
stages of LP rotor might also be having deposits.
Feedwater heater performance: Variation in the effectiveness of feedwater heaters from the
design was observed. This was due to improper extraction parameters, leakages in internals
of heaters. At some plants, the drip was not maintaining and the heaters were getting
bypasses. Also, some were avoiding the use of heaters in the circuit. These all resulted in
thermal loss.
Makeup water: Makeup water was observed high in plants. It was mainly due to various
leakages in the system; boiler blow down, soot blowing and valve passing. The additional
make up flow resulted in higher feed water thermal duties which cause additional extraction
flows and higher pump duty requirement, in turn increasing the heat rate.
23 | P a g e
Superheater and reheater spray: the spray was observed on higher side. This caused higher
make up water requirement. Also, it contributed to a significant heat loss.
Insulation and cladding: In some plants, insulation was also one of the reasons of heat loss.
Damaged insulation in some of the locations such as ducts, steam pipes, etc. resulted in
higher heat loss and also results in poor performance of certain equipment.
5.3. Measures Recommended
Based on the gap analysis in each plant, recommendations were made. These
recommendations were presented before the plant management and an action plan was
agreed upon. They were mainly divided into two categories, namely short term and long term
recommendations. The short term recommendations are those which mostly relates to
operating practices, can be implemented immediately at lesser cost, permitting picking up of
low hanging fruits. The long term recommendations cover overhauling and retrofit in the
plant. Some of the recommendations are mentioned below
Partial load operation: Partial load due to internal reasons can be controlled by proper
maintenance of equipment reducing breakdowns, and increasing individual equipment
efficiency.
Coal: To improve coal quality coal blending should be practiced- a) internal blending and b)
external blending. Use of blended coal in proper ratio can improve combustion efficiency.
This will also average the generation cost by decreasing heat rates. Proper selection of mills
in case of internal blend will also improve performance parameters. Mill load biasing to be
done based on GCV of imported coal to avoid clinkering and slagging.
Low Vacuum: Condenser cleaning needs to be done in most cases. Condenser vacuum can
be improved by high pressure jet cleaning and scale removal. Online tube cleaning system
can be installed to have regular cleaning. Tube leakages can be attended. Performance of
individual cooling tower cell to be restored by taking necessary repair work one by one in the
running unit.
Boiler combustion: Mill combination to be checked and control the fuel air damper and aux
air damper to maintain furnace left-right uniform temperature and avoid high variation in
furnace temperature.
Soot blowing optimization: Soot blowing to be made a regular practice. Usages of LR soot
blowers to be adopted to ensure adequate cleaning of Ist and 2nd pass. LRSB’s to be
operated once a week.
Air heater performance: Improved monitoring of combustion regime and APH performance
shall reduce flue gas temperature leaving air heater and reduce boiler losses. For improving
APH’s performance APH soot blowing to be done regularly. Additional zirconia probes can
be installed at inlet of each APH to get better insight into excess air at which optimum boiler
operation is being achieved. Air ingress across seals to be controlled. APH baskets to be
checked and replaced during overhaul.
24 | P a g e
Degradation in turbine performance: To improve HP and IP turbine efficiency complete
overhauling of turbine is desirable. Turbine first stage pressure was high in some units which
indicate salt deposits. To rectify this, overhauling of complete turbine is recommended.
Feedwater heater performance: The terminal temperature difference of HP heaters in some
plants was observed to be negative, which is impossible. This is due to faulty measuring
instruments and needs calibration during shutdown.
Makeup flow: Makeup water consumption to be monitored periodically using deaerator drop
test. Isolation checklist to be developed for periodic checking to eliminate passing of drains,
control valves and isolation valves, thereby minimizing heat rate loss.
Superheater and reheater spray: SADC operation should be modulated to achieve better
control of furnace exit temperature and to reduce spray
Insulation and cladding: Insulation to be restored during running /opportunity shutdown as
may be possible to reduce heat loss.
5.4. Conclusion and Findings As a result of implementation of measures, there was a significant improvement in heat rate
thereby leading to improvements in efficiency. The table below gives an overview of
improvements in parameters.
ITEM Unit Initiated by IGEN
Due to change in Coal Quality
Unaccounted Overall
Heat Rate Improvement (from operating) %
2.77 1.55 0.42 4.74
Efficiency Improvement (from operating) %
2.86 1.58 0.57 5.01
Energy toe/year 40002.06 21332.45 6234.62 67569.13
Coal Savings t/year 119757.15 65026.52 18156.78 202940.45
CO2 Savings t/year 176530.85 91910.70 27698.03 296139.58
Monetary Savings Cr Rs./Year 40.62 21.66 6.28 68.56
Monetary Savings Mio Euro/year
5.80 3.09 0.90 9.79
Table 11: Achievements of model power plant
It can be observed from the table above that with the activities on these plants, 296
thousand tonnes of CO2 emission reduction per year was achieved. This meant a savings of
Rs. 68.5 Crores per year.
Apart from the direct improvement in heat rates and savings, an improved O&M practices
have been developed in regard to, heat rate deviation monitoring, mill performance
monitoring & testing, coal blending process, air ingress survey across flue gas path,
strengthening on line measurement scheme across air heaters, soot blowing, condenser
tube cleaning, strengthening on line measurement across regenerative feed water heaters,
combustion stability.
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7. Implementation of a demonstration boiler performance optimization
system (BPOS)
Apart from the model power plants, one unit of Suratgarh super thermal power plant was
undertaken for implementation of state of art Boiler performance optimization system
(BPOS) as pilot project. BPOS is an intelligent soot blowing software which optimizes the
entire process of soot blowing. This leads to an improvement in boiler efficiency thereby
leading to a better heat unit rate and efficiency.
The main objective was to demonstrate and assess the technical viability and financial
attractiveness for retrofitting Indian power plants with online BPOS in closed loop mode for
reducing the environmental pollution and greenhouse gases and document the lessons
learned. The system was implemented in 250 MW Unit#6 of Suratgarh Super Thermal
Power Station (SSTPS) of Rajasthan Rajya Vidyut Utpadan Nigam Ltd (RVUN).
Duration of the project was 9 months. Project was started in December 2013 with kick off
meeting at site and site acceptance test was carried out successfully in August 2014. The
commissioning of the system and necessary modification of DCS has been done during
operation of the unit without any unit shutdown.
In a coal-fired boiler, the deposition of ash and soot on the boiler tubes can lead to a
reduction in boiler efficiency. Thus, cleaning of heating surfaces is one of the most important
boiler auxiliary operations for boiler efficiency optimization. BPOS has first principle based
thermodynamic boiler model which calculates efficiency of the heating surfaces. The
cleaning of the furnace is done automatically based on these calculated results and not on
time basis.
7.1. Approach
Prior to this project the control and instrumentation related to soot blowing were usually
treated as isolated systems and performance of the boiler was calculated manually. The
following stems were undertaken for installation and commissioning of this demonstrational
project of BPOS under IGEN Phase-II.
i) Plant basis data collection and analysis
ii) System installation and data acquisition.
iii) Preparation of thermodynamically boiler model and installation on site
iv) Commissioning in open loop
v) Commissioning in closed loop.
The activities were started with the signing of MoU between GIZ and RVUN at CEA’s office
and handing over of license. At various stages the OEM was also involved and several
discussions were held. The demonstrational project was completed with the successful
commissioning and site acceptance test.
7.2. BPOS System Description
Boiler performance Optimization System is an online performance monitoring and
optimization system for the Boiler operation.
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The main modules covered under BPOS system is given below:
Data Management System (SRx) with Data Visualizer (SRxVIS)
Data Validation System (SRv)
Boiler Performance Monitoring System (SR::BPOS)
Soot Blowing Optimization System (SR::BCM)
Boiler Offline What-If Analysis (SR::What if)
Excel Reports
Ebsilon® Professional Thermodynamic Boiler calculation
For the evaluation of boiler operation a detailed thermodynamic model of the relevant boiler
components has been built by powerful software program Ebsilon® Professional.
Ebsilon® Professional runs in the background and interfaces with SRx to get the
measurement values and writes the results. All relevant model results are available in
process screens of BPOS.
Within Ebsilon® Professional the model has been configured graphically (Fig. 6 & 7) during
its implementation. Boiler has been constructed from the main components available in
Ebsilon® Professional like heating surfaces, injections, combustion chamber as well as the
connecting pipes.
System Modules
The Figure below shows the basic, optimization and performance analysis modules of
BPOS. All the modules interface with central Data Management System to take data and
write back the results. The sequence of operation is following.
Data from DCS is collected in Data Management System. Collected data is validated by
Data validation module. Validate data is taken by boiler model, boiler efficiency and other
performance parameters are calculated by boiler performance monitoring module. The
results are presented in excel reports. Soot blowing optimizer uses these results to generate
soot blowing recommendation. Boiler What-if Analysis module is an offline tool which is used
on used demand.
Figure 7: BPOS Modules
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Hardware Description
The figure below shows the system configuration of BPOS at Suratgarh.
Figure 8: BPOS Hardware
There is one BPOS server connected to DCS network through a Firewall and total three
numbers of BPOS clients are connected to BPOS sever. BPOS server and one client is
located in engineering room while two BPOS client have been installed in control room.
RVUN has provided a broadband connection which has been also connected to BPOS
server through firewall.
7.3. Conclusion and Benefits
Monitoring
After the successful completion of BPOS the results were compared. Two time periods have
been selected for analysis of the data. The first time period is from 6th to 17th June which is
the time period before commissioning of BPOS. The second time period is from 20th to 30th
August which is the time period after commissioning of BPOS. The selection of both periods
was made to ensure that the boiler has been operated under similar conditions in respect to
load, ambient temperature and the coal GCV. Additionally both periods should have the
same duration. Report was generated from BPOS system for the above mentioned periods.
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Screenshots of the two reports is shown here as Fig. 14 & 15. Transient state data has not
been taken into consideration for comparison of above periods. The average values of unit
load and boiler efficiency shown in the below table has been taken from generated BPOS
reports.
For the comparison of boiler efficiency the actual value of efficiency in the period after BPOS
has been corrected to take into account the different conditions.
Benefits
a) Boiler Efficiency Improvement - Suratgarh Unit-6 already operates with high boiler
efficiency which is even better than the design. Despite of this the improvement in
efficiency by 0.18% has been achieved by use of BPOS.
b) Heat rate Improvement - the improvement of unit heat rate due to improvement of boiler
efficiency by 0.18 % amounts to 4.54kcal/kWh in case of this unit.
c) Monetary savings - The improvement of efficiency leads to reduction of coal needed for
the generation of same amount of power. Considering that the coal burnt in Unit No. 6
cost Rs. 5000/ton, an efficiency improvement of 0.18 percent means decrease in coal
consumption by 1989.46 tons/year for a savings of Rs. 99.47 Lac per year.
d) Environmental Savings - The improvement in the boiler efficiency has the positive
impact on environment as well. The reduction of coal consumption for the same
generated output leads to reduction of environmental pollution and greenhouse gases.
Given that the saving of coal per year is 1989.46 tons/ year and carbon percentage in
coal used in Suratgarh is 47.2 %, the saving of CO2 emission amounts to 3441 tons per
year.
e) Improving Operational Practices - The installation of BPOS improved the operational
practices. The cleaning of furnace is now carried out automatically based on requirement
from thermo dynamical point of view.
f) Automatic Efficiency Reporting by Email – Reports with all relevant boiler parameters
are automatically generated and sent by email to plant officials on daily basis. Thus the
information is readily available at the user desk.
g) Offline What-If Analysis – Plant engineers can examine now the impact of different
operational scenarios on efficiency before their implementation during the real operation.
h) Thermodynamic transparency of the boiler – BPOS calculates online parameters
such as efficiency of the heating surfaces, temperature profile on the flue gas side and
air ingress to furnace. These parameters are not available in the DCS systems and
cannot be obtained without a boiler model.
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i) Measurements validation – BPOS provides the information about the quality of the
measurements and provide replacement values for bad sensors so that calculations are
done with high accuracy and availability.
j) Lifetime Storage of Data - BPOS is capable of storing the data for the lifetime of the
power plant and data can visualized very quickly. Thus analysing of boiler operation from
overhaul to overhaul can be done very easily.
Conclusion
It is known that if the boiler is kept clean, its efficiency will increase on account of better heat
transfer. Where, practicing soot blowing daily or once in a shift increases the steam
consumption, avoiding soot blowing will invite depositions on boiler tubes ultimately leading
to improper heat transfer. Hence, it becomes utmost important to use the soot blowing
operation when and where it is needed the most.
The above result clearly shows this advantage of BPOS over conventional practice of soot
blowing.
The situation before BPOS differed a lot in terms of practice. The soot blowing operation was
done manually. Wall blowing was done selectively depending on the availability of wall
blowers and frequency varied from weekly to fortnightly. If lower mills are in operation, wall
blowing is avoided so that reheat temperature does not go down further. Frequency of soot
blowing in LRSB varied from fortnightly to monthly.
The situation after BPOS became more optimised where the soot blowing was controlled in
close loop of BPOS. The system generated commands of soot blowing depending upon the
need in specific areas. This optimised the steam and time consumption. Also, it avoided the
depositions in boiler and resulted in higher boiler efficiency.
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Abbreviations
APH Air preheater TTD Terminal temperature
difference
AUX Auxiliary UBC Un-burnt carbon
BFP Boiler feed pump WW Water wall
BA Bottom ash WB Wind box
CEP Condensate extraction pump WBT Wet bulb temperature
CHP Coal handling plant GHG Greenhouse gas
CO
COH
Carbon monoxide
Capital overhaul
PPOC Power Plant Optimization
Component
CO2 Carbon dioxide IGEN Indo German Energy
Programme
CW Cooling water CEA Central Electricity Authority
DCS Distributed control system SB Soot blower
DCA Drain cooler approach toe Tonnes of oil equivalent
DM Demineralised
ESP Electro-static precipitator
EA Excess air
FA Fly ash
FD Forced draft
FG Flue gas
FW Feed Water
GCV Gross calorific value
HBD Heat balance diagram
HGI Hard groove index
HPH High pressure heater
HPT High pressure turbine
ID Induced draft
IGV Inlet guide vane
IPT Intermediate pressure turbine
KVA Kilo volt ampere
LPH Low pressure heater
LPT Low pressure turbine
LTSH Low temperature super heater
LMTD Log mean temperature difference
mmHg Millimetre of mercury
mmwc Millimetre of water column
MS Pressure Main steam pressure
MS Temperature Main steam temperature
MU Million unit
PA Primary air
PLF Plant load factor
PPD Predicted performance data
R&M Renovation and Modernization
RH Reheater
RPM Revolution per minute
RW Raw water
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Annexures
Annexure 1: 85 Units Mapped under IGEN Phase I
Sl No. State Board/ Electricity Gen. Company
Power Station Unit size MW
Unit No
1 PSEB Gurunanak Dev. Thermal Power Plant, Bathinda
110 2
2 MAHAGENCO Khapar Kheda Thermal Power Plant 210 1
3 WBPDCL Kolaghat Thermal Power Plant 210 3
4 TNEB Mettur Thermal Power Plant 210 1
5 MAHAGENCO Nasik Thermal Power Plant 210 3
6 HPGCL Panipat Thermal Power Plant 210 5
7 OPGLC IB Valley Thermal Power Plant 210 1
8 PSEB Guru Hargobind Thermal Power Plant 210 1
9 NLCL Neyveli Lignite Corporation 210 3
10 NLCL Neyveli Lignite Corporation 210 7
11 MBEB Satpura Thermal Power Plant 210 7
12 RSEB Suratgarh Thermal Power Plant 250 1
13 TNEB Tuticorn Thermal Power Plant 210 1
14 MAHAGENCO Chanderpur Thermal Power Plant 500 6
15 MAHAGENCO Chanderpur Thermal Power Plant 210 4
16 MAHAGENCO Koradi Thermal Power Plant 200 5
17 WBPDCL Bandel Thermal Power Plant 210 5
18 MAHAGENCO Bhusawal Thermal Power Plant 210 3
19 CSEB Korba Thermal Power Plant 210 4
20 PSEB Guru Gobind Singh Thermal Power Plant 210 6
21 GSECL Ukai Thermal Power Plant 210 5
22 TNEB North Chennai Thermal Power Plant 210 1
23 GSECL Ukai Thermal Power Plant 200 4
24 GSECL Ukai Thermal Power Plant 210 1
25 DVC Bokaro Thermal Power Plant 210 1
26 GSCEL Wanakbori Thermal Power Plant 210 4
27 GSCEL Wanakbori Thermal Power Plant 210 3
28 DVC Durgapur Thermal Power Plant 210 5
29 DVC Meja Thermal Power Plant 210 4
30 APGENCO Vijayawada Thermal Power Plant 210 1
31 APGENCO Kothagudem Thermal Power Plant 250 10
32 CSEB Korba East Thermal Power Plant 120 6
33 UPRVUNL Anpara Thermal Power Plant 210 1
34 UPRVUNL Anpara Thermal Power Plant 500 5
35 UPRVUNL Obra Thermal Power Plant 200 13
36 APGENCO Vijayawada Thermal Power Plant 210 5
37 APGENCO Kothagudem Thermal Power Plant 250 9
38 APGENCO Rayalseema Thermal Power Plant 210 1
39 WBPDCL Bakreshwar Thermal Power Plant 210 2
40 MAHAGENCO Parli Thermal Power Plant 210 3
41 KPCL Raichur Thermal Power Plant 210 3
42 KPCL Raichur Thermal Power Plant 210 4
43 HPGCL Panipat Thermal Power Plant 110 3
44 APGENCO Kothagudem Thermal Power Plant 120 8
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Sl No. State Board/ Electricity Gen. Company
Power Station Unit size MW
Unit No
45 UPRVUNL Obra Thermal Power Plant 110 8
46 UPRVUNL Paricha Thermal Power Plant 210 3
47 UPRVUNL Paricha Thermal Power Plant 110 1
48 GSECL Dhuvaran Thermal Power Plant 140 5
49 GEB Gandhinagar Thermal Power Plant 120 2
50 GSECL Wanakbori Thermal Power Plant 210 1
51 TVNL Tanughat Thermal Power Plant 110 2
52 GSECL Ukai Thermal Power Plant 120 1
53 HPGCL Panipat Thermal Power Plant 250 8
54 GIPCL Surat Lignite 125 2
55 GSECL Sikka Thermal Power Plant 120 1
56 DVC Chandarapura Thermal Power Plant 140 3
57 MPPGCL Sanjay Gandhi Thermal Power Plant 210 1
58 MPPGCL Amarkantak 120 3
59 WBPDCL Santaldhi Thermal Power Plant 120 1
60 DVC Durgapur 140 3
61 APGENCO Kothagudem Thermal Power Plant 120 6
62 APGENCO Rayalseema Thermal Power Plant 210 3
63 OPGCL IB Valley Thermal Power Plant 210 2
64 UPRVUNL Obra Thermal Power Plant 200 10
65 UPRVUNL Panki Thermal Power Station 105 4
66 RVUNL Kota Thermal Power Plant 110 2
67 RVUNL Kota Thermal Power Plant 210 4
68 UPRVUNL Paricha Thermal Power Plant 210 4
69 TNEB North Chennai Thermal Power Plant 210 4
70 TNEB Mettur Thermal Power Plant 210 4
71 TNEB Ennore Thermal Power Plant 110 5
72 MAHAGENCO Chandarpura Thermal Power Plant 500 7
73 MAHAGENCO Koradi Thermal Power Plant 210 6
74 PSEB Bathinda Thermal Power Plant 110 1
75 APGENCO Vijayawada Thermal Power Plant 210 6
76 CSEB Korba Thermal Power Plant 210 2
77 PSEB Ropar Thermal Power Plant 210 2
78 PSEB Ropar Thermal Power Plant 210 3
79 MAHAGENCO Kapar Kheda Thermal Power Plant 210 2
80 MAHAGENCO Nasik Thermal Power Plant 140 1
81 MAHAGENCO Nasik Thermal Power Plant 210 5
82 RUVNL Kota Thermal Power Plant 195 6
83 UPRVUNL Anpara Thermal Power Plant 500 4
84 RSEB Suratgarh Thermal Power Plant 250 2
85 MAHAGENCO Chanderpur Thermal Power Plant 500 5
Total 14285
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Annexure 2: Formulae and Calculations Gross generation = G kW Reduction in TG heat rate = A kcal/kWh (From Model Analysis) Boiler efficiency = B % (From Model Analysis) Gross calorific value =GCV kcal/kg Cost of fuel = Cf Rs/tons Reduction in heat Input to boiler (HinBoil) = (G*365*24*PLF*A) / B Reduction in fuel consumption (Fcon) = HinBoil / GCV (kg) = HinBoil / GCV /1000 (tons) Monetary saving = Fcon* Cf/10000000 Crores of Rs. = (Fcon* Cf /70)/1000000 million € C + O2 = CO2
Carbon in Coal = XC 1 kg of fuel = (44/12)* XC of CO2 Total CO2 savings (tonnes/ year) = (44/12)* XC *coal savings per year Coal savings (tonnes/ year) = (ΔHR/ coal GCV) *load* 8760 * PLF Tonnes of oil equivalent (toe) per year = (ΔHR/ oil GCV) *load* 8760 * PLF Average coal GCV = (coal GCV before + coal GCV after)/2 Average carbon % in coal = (carbon % before + carbon % after)/2
References
1. http://en.wikipedia.org/wiki/List_of_countries_by_electricity_production 2. CEA- Growth of Electricity Sector in India from 1947-2013
http://www.cea.nic.in/reports/planning/dmlf/growth.pdf 3. CEA- Executive Summary Feb-2015
http://www.cea.nic.in/reports/monthly/executive_rep/feb15.pdf 4. CEA- Executive Summary Mar-2015
http://www.cea.nic.in/reports/monthly/executive_rep/mar15.pdf 5. The Final Report of the Expert Group on Low Carbon Strategies for Inclusive Growth
http://planningcommission.nic.in/reports/genrep/rep_carbon2005.pdf 6. Model Power Plant Reports IGEN Phase-II_ Durgapur TPS 7. Model Power Plant Reports IGEN Phase-II_ Bhusawal TPS 8. Model Power Plant Reports IGEN Phase-II_ Mettur TPS 9. Model Power Plant Reports IGEN Phase-II_ Giral TPS 10. Report on Introduction of Measures for improved PLF and availability 11. Case Study Reports IGEN Phase-II 12. Compendium of Case Studies IGEN Phase-II 13. Mapping Reports IGEN Phase-II 14. Summary of mapping Reports IGEN Phase-II 15. Feedback templates from utilities 16. Presentations of utilities from IGEN Conclave, January 2014
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Imprint
The findings and conclusions expressed in this document do not
necessarily represent the views of the GIZ or BMZ.
The information provided is without warranty of any kind.
Published by
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Internationale Zusammenarbeit (GIZ) GmbH
Indo German Energy Programme (IGEN)
Power Plant Optimisation Component
Registered offices: Bonn and Eschborn, Germany
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