STATUS AND SCOPE OF
PARABOLIC DISH SOLAR
COLLECTORS
-VANITA
N. THAKKAR
ASSOCIATE PROFESSOR
MECHANICAL ENGINEERING DEPARTMENT,
BABARIA INSTITUTE OF TECHOLOGY,
VARNAMA, VADODARA
AND
MEMBER, GOVERNING COUNCIL,
SOLAR ENERGY SOCIETY OF INDIA
CONTENTS
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INTRODUCTION
LITERATURE REVIEW :
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CONCENTRATED SOLAR POWER : TYPES, ADVANTAGES AND
DISADVANTAGES OF SCs
CSP – WORLD-WIDE
VANITA N. THAKKAR
CSP IN INDIA
CSP IN MANUFACTURING INDUSTRY
REFERENCES
2
INTRODUCTION

About 5,000 trillion kWh per year : solar energy incident
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over India’s land area,

An average 5-7 kWh/m2/day
: Available in most parts of
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India.
By 2030, India’s population will surpass that of China.

By 2050, India will consume 1/3rd of the total global energy
VANITA N. THAKKAR

demand [5].

Focus on Solar Thermal Applications due to :

abundant solar radiation,

clean character of solar energy,

high cost of fossil fuels,

negative emission consequences
3
CONCENTRATED SOLAR POWER (CSP):
Solar Energy
Technology
Direct
Conversion
Concentrating
Collectors
(Concentrators)
Box Type
Cookers
Further
classification
…..
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Water Heating
Systems
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Solar Thermal
Conversion
Systems
Flat Plate
Collectors
Air Dryers
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Solar concentrator is a
device that allows the
collection of sunlight
from a large area and
focusing it on a smaller
receiver or exit [18].
Solar
Photovoltaic
4
TYPES OF SOLAR CONCENTRATORS
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In past four decades : lot of developments in designs of the solar
concentrators – for thermal as well as PV applications.
Classification of Solar Concentrators based on optical principles
[18]:
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VANITA N. THAKKAR
5
ADVANTAGES AND DISADVANTAGES OF
SOLAR CONCENTRATORS
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VANITA N. THAKKAR
6
PARABOLIC DISH SOLAR CONCENTRATORS
Parabolic Dish Solar Concentrators (PDSCs) :
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
high conversion efficiencies and operating
–
around
750oC
at
annual
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temperatures
efficiency of 23%-29% peak.
Research is on : some prototypes tested world-
VANITA N. THAKKAR

wide.

High investment costs, almost twice as those for
parabolic troughs.

PDSC industries and initiatives are mostly
confined to the US and Europe.
7
PARABOLIC DISH SOLAR CONCENTRATORS
(CONTD.)
PDSCs for process heat requirements of community,
industrial and commercial establishments like
Process heating, Cooling, Community Cooking,
Laundry Applications, etc. is an emerging and
exciting opportunity in India.
THIS PRESENTATION TRACES DEVELOPMENT
OF PDSC TECHNOLOGY AND EXPLORES SCOPE
OF WORK IN THE FIELD, WITH SPECIAL FOCUS
ON INDIA.
VANITA N. THAKKAR

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
High potential for using PDSCs in various
industries, in India, encourages research and need
of development.
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
8
REVIEW OF CSP TECHNOLOGY
in
:
GENERATION
OF
Most research on CSP : use in generation of electricity such as,
maintenance [30 - Leonard D. Jaffe, Test results on
parabolic dish concentrators for solar thermal
power systems, Solar Energy, Volume 42, Issue 2,
9
1989, pp – 173–187].
VANITA N. THAKKAR
Results of development testing of various solar thermal
parabolic dish concentrators, mostly designed for
generating low cost electricity, using dish-mounted
Rankine, Brayton or Stirling cycle engines. Tests provide
important operating information for developing
concentrators with improved performance and reduced
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
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Most
fuel
consumption
ELECTRICITY.
REVIEW OF CSP TECHNOLOGY (CONTD.)

Innovation in CSP technologies over the last decade
Improvements in reflector and collector design
materials,

heat absorption and transport

power production

thermal storage

Many applications to be integrated with CSP regimes to
conserve (and sometimes produce) electricity suggested and
implemented, giving environmental benefits by limited fossil
10
fuel usage – details in references [1-54].
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
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
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[31 – David Barley, Ruxendra Vidu, Pieter Stroeve,
Innovation in concentrated solar power, Solar
Energy Materials and Solar Cells, Volume 95, Issue 10,
October 2011, pp – 2703–272], such as,
REVIEW OF CSP TECHNOLOGY (CONTD.)

analyzes performance of parabolic mirror, receiver, Stirling
engine, and parasitic power consumption to predict the net
power produced,

includes location dependent properties affecting performance :
direct normal insolation,

ambient temperature,

density of air (altitude),

sun elevation angle,

wind speed.
Numerous projects implemented world-wide by research centres,
universities and companies to investigate and analyze reliability
11
and performance of CSP : some shown in table below [18].
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
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
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
A thesis : Stirling Dish System Performance Prediction Model –
energy prediction model created using TRNSYS for solar Stirling dish
systems for prediction of location dependent long term performance [16].
(CONTD.)
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VANITA N. THAKKAR
12
CSP IN INDIA : REVIEW (CONTD.)

Pioneering work – use of Scheffler Dish for
SOLAR COOKING : introduced two decades
back by Shree Deepak Gadhia – Gadhia Solar,
Valsad, Gujarat for community cooking.
Shortcomings overcome :
of box type solar cooker overcome : could only boil and
roast the food

mini concentrating dish type solar cookers : cumbersome
outdoor usage.
Successfully used for other applications
desalination, food processing, etc.
like
VANITA N. THAKKAR

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
India – Dish Technology for generating electricity :
yet to get established.
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
13
CSP IN INDIA : REVIEW (CONTD.)
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14
CSP IN INDIA : REVIEW (CONTD.)
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15
CSP IN INDIA : REVIEW (CONTD.)
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
Several Solar steam cooking systems of different
sizes to cook for from 500 to 40,000 people, for
different user groups like, Temples, Ashrams, Army
Camps, Hospitals, Canteens, Hostels etc. [46]
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
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Parabolic collectors using thermic fluid as working
medium for cooking : developed and successfully
working at Muni Seva Ashram, Goraj, Gujarat to
overcome the limitations of steam as working
medium – better thermal storage, transfer and
control [47].
16
CSP IN INDIA : REVIEW (CONTD.)
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17
CSP IN INDIA : REVIEW (CONTD.)
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18
CSP IN INDIA : REVIEW (CONTD.)
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SOLAR COOKING - THERMIC FLUID (FROM SPDC) IN
JACKETED VESSELS FOR COOKING - BOILING-STEAMING AT
GORAJ CANTEEN
19
CSP IN INDIA : REVIEW (CONTD.)
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20
PAN FOR COOKING - HEATED BY THERMIC FLUID (FROM SPDC)
COIL BELOW ITS SURFACE
CSP IN MANUFACTURING
INDUSTRY : REVIEW (CONTD.)
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MANUFACTURING INDUSTRY : one third of
total energy use worldwide.
 In energy intensive sectors : ferrous and nonferrous metals, chemicals and petrochemicals, nonmetallic mineral materials, and pulp and paper, etc. –
energy costs -> major part of total production
costs.
 Industrial production : projected increase -> factor of
four between now and 2050.
 RE
: used in power generation and for
residential applications, limited use in industry.

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21
CSP IN MANUFACTURING
INDUSTRY : REVIEW (CONTD.)
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 Biomass
: most significant RE contribution to
industry (8% - 2007).
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 RE
in industrial applications : to be used upto
21% of all final energy use by 2050.
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 Feedstock
in manufacturing industry in
2050 to be of renewable origin, major
contributions from Biomass feedstock.
 Process
energy, process heat from solar
thermal installations and heat pumps [42].
22
SECTOR-WISE ENERGY CONSUMPTION PATTERNS
IN THE INDUSTRY – WORLD-WIDE
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Regional and Sectoral breakdown of Biomass potential for
process heat in industry in 2050, excluding interregional trade,
UNIDO Analysis [35].
23
CSP IN MANUFACTURING INDUSTRY IN
INDIA : REVIEW (CONTD.)


Industrial Sectors Promising for
Commercialization
of
Solar
Energy in India shown in Table:
Identified on :
 Grade
of
heat
required
(high/low),
 Growth prospects of the sector
and
 Ongoing interventions
by weighted parametric studies [44]:
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
Only 25 to 30% saving by Solar
Concentrators, can reduce import of
4.5 million tons oil per year : ≈ 6%
of our oil imports [45].
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
Industrial Process Heat (IPH)
applications up to 250°C : 15 to 20%
of this.
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
India : 100 Million Tons oil per
year.
24
(CONTD.)
other References :
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 Some
 Prototype
Instantaneous efficiency of 63.9%

Can be used for heating boiler feed
water, laundry applications and other
steam generation applications [48].
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
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design of solar parabolic dish
collector with truncated cone shaped
helical coiled receiver made up of
copper, coated with nickel chrome at
focal point.
25
(CONTD.)
of
ARUN brand of
for
pasteurization
milk
at
Mahanand
Dairy in Latur,
Maharashtra
[49].
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of
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SCS
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Development
26
(CONTD.)
A

Calculated overall heat transfer co-efficient :
varies from 130 to 180 W/m2 K for actual
climate conditions at Tiruchirappalli,
India.

Thermal efficiency of collector = 60%

Cost = half the cost of a collector available
in market with same specifications.
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Absorber, made of aluminum alloys and
coated with black paint.
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
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parabolic dish collector developed from
low cost technology and tested outdoors[50].
27
o THE MEGAWATT SYSTEM :
Megawatt a Delhi-based Co.,
parabolic
collector
of
dish
type
90m2
area.
tested
at
Center
of
Energy
Ministry
and
of
Renewable
Energy (MNRE).
Proposed field testing under
R & D support of MNRE for
industrial
heating
applications.
o Specifications
of
a
typical
Parabolic Solar Concentrator –
in the Table.
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New
Solar
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Prototype : built and being
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has developed indigenous
28
TESTING OF PDSC:
Very little has been done on testing of PDSCs
Testing of SK-14 and PRINCE-15 SCs : comparing
performances of two different geometries in actual
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working conditions [51].

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Testing Proposal for Paraboloidal solar concentrators by
Mullick et al (1991) [52]. Two parameters –

optical efficiency factor (F’ηo) – gives theoretical upper limit of the
overall efficiency of concentrator


the heat loss factor (F’UL).
Improvement in this procedure : as worked out by Paul A.
Funk.
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
29
TESTING OF PDSC : (CONTD.)
Paul A. Funk defined two figures of merits : F1 (NoLoad Condition) and F2 (Load Condition) as operating
parameters [53, 54].
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
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Time, s
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Total Solar Radiation (W/m2)
Beam Radiation (W/m2)
Start temperature of water °C
End temperature of water °C
Efficiency with
beam radiation %
30
CONCLUSION
Solar Energy Technology has an important role to
play in the present Energy and Environment crises.
Solar Concentrator Technology has good potential
for various applications.
Parabolic Solar Dish Concentrators can be very
useful in Industrial Process Heat applications, which
use about 20% of total oil consumption in India.

If only 25 to 30% of this can be saved by putting up
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
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
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
Solar Concentrators, it will save import of 4.5 MT oil
per year, which is about 6% of our oil imports.
31
CONCLUSION (CONTD.)
of Research and Development is
ample in this area, owing to the fact that very
of it has been done in the US and
Europe.
 With
the help of indigenous developments
in such fields, India can step forward towards
self-reliance in Energy Sector.
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 Most
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little work has been done on it.
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 Scope
32
REFEFENCES
1.
3.
5.
7.
8.
9.
10.
11.
12.
VANITA N. THAKKAR
6.
ICORE-2013
4.
02/12/2013
2.
Historical Perspectives of Energy Consumption, downloadable from : http--www_wou_edulas-physci-GS361-graphics-Production_vs_consumption_jpg.html.
The Need Project, Manassas, VA 20108 (USA) (2008), Intermediate Energy Infobook, 44-48,
1-800-875-5029.
The Energy and Resources Institute, India Habitat Centre, Lodhi Road, New Delhi 110003
(2006), Liquid Biofuels for Transportation : India country study on potential and
implications for sustainable agriculture and energy. TERI.
Overall : World Energy Consumption (MTOE), Source : CMIE, April 2001, downloadable from :
www.natcomindia.org/energy2.htm.
M. P. Ram Mohan, Linoj Kumar (2005) (TERI, India), Biofuels : The Key to India’s
Sustainable Energy Needs, RISO International Energy Conference 2005, May 22-25, 2005,
Denmark.
Mathew R. Delvin (2008), Investigation of an alpha-parabolic solar concentrator dish,
Thesis submitted for Master of Science (Engineering) at Lehigh University.
R. Winston, J.C. Minano and P. Benitez (2005), Nonimaging Optics, Elsevier Academic Press,
pp. 1-217.
D. Abbott (2009), Keeping the Energy Debate Clean : How Do We Supply the World’s
Energy Needs?, Proceedings of the IEEE, 98(1): 42-66.
Q. Liu, G. Yu, and J.J. Liu (2009), Solar Radiation as Large-Scale Resource for EnergyShort World, Energy & Environment, 20(3): 319-329.
N.J. Ekins-Daukes (2009), Solar Energy for Heat and Electricity: The Potential for
Mitigating Climate Change, Briefing Paper No 1: 1-12.
REN21 Renewables 2007 Global Status Report, Renewable Energy Policy Network for the
21st
Century
(REN21),
2007,
downloadable
from
:
http://www.ren21.net/pdf/RE2007_Slides.pdf.
33
F. Jiang and A. Wong (2005), Study on the Performance of Different Types of PV Modules
in Singapore, Proceedings of International Power Engineering Conference (IPEC 2005), Singapore.
REFEFENCES (CONTD.)
13.
16.
18.
19.
20.
21.
22.
23.
VANITA N. THAKKAR
17.
ICORE-2013
15.
02/12/2013
14.
F. Kamel Abdalla and P. Wilson (2002), Cost of kWh Produced and Payback Time of a PVSolar-Thermal-Combined Rooftop Collector at Different Locations in New Zealand, EEA
Annual Conference & Trade Exhibition 2002: Meeting the Challenges of Growth, Christchurch, New
Zealand.
W. Guter, J. Schöne, S.P. Philipps, M. Steiner, G. Siefer, A. Wekkeli, E. Welser, E. Oliva, A.W. Bett,
and Frank Dimroth (2009), Current-Matched Triple-Junction Solar Cell Reaching
41.1%Conversion Efficiency Under Concentrated Sunlight, Applied Physics Letter, 94, 22,
2009.
R.M, Swanson (2000), The Promise of Concentrators, Progress in Photovoltaics: Research and
Applications, 8: 93-111.
Paul R. Fraser (2008), Stirling Dish System Performance Prediction Model, A thesis
submitted in partial fulfillment of the requirements for the degree of Master of Science (Mechanical
Engineering) at University of Wisconsin-Madison.
Mancini, Thomas, et al., Dish-Stirling Systems: An Overview of Development and Status.,
Journal of Solar Energy Engineering 125 (May 2003), pp-135-151.
F. Muhammad-Sukki, R. Ramirez-Iniguez, S.G. McMeekin, B.G. Stewart & B. Clive, Solar
Concentrators, International Journal of Applied Sciences (IJAS), Volume (1): Issue (1).
C.F. Chen, C.H. Lin, H.T.Jan & Y.L. Yang (2009), Design of a Solar Concentrator Combining
Paraboloidal and Hyperbolic Mirrors Using Ray Tracing Method, Optics Communication,
282:360-366, 2009.
G. Sala, D. Pachón and I. Antón (2000), Book 1: Classification of PV Concentrators, Test,
Rating, and Specification of PV Concentrator Components and Systems, C – Rating Project, (2000).
downloadable at: http://www.ies-def.upm.es/ies/CRATING/crating.htm.
SolarEmpower Ltd. Downloadable at : http://www.solarempower.com.
J.C. Miñano and P. Benítez (2008), High Concentration Photovoltaics: Potentials and
34
Challenges, Webinar in Photovoltaic Concentration, USA, 2008.
A. R. Mahoney, J.E. Cannon and J.R. Woodworth (1993), Accelerated UV-aging of Acrylic
Materials used in PV Concentrator Systems, Proceedings in the 2 3rd IEEE Photovoltaic
Specialists Conference, Louisville, Kentucky, USA, 1993.
REFEFENCES (CONTD.)
24.
26.
28.
30.
31.
32.
33.
34.
VANITA N. THAKKAR
29.
ICORE-2013
27.
02/12/2013
25.
A. Terao, W.P. Mulligan, S.G. Daroczi, O.C. Pujol, P.J. Verlinden and R.M. Swanson (2000), A
Mirror-Less Design for Micro-Concentrator Module, Proceedings of the 28th IEEE
Photovoltaic Specialists Conference, Anchorage, Alaska. 2000.
A.J. Chatten, K.W.J. Barnham, B.F. Buxton, N.J. Ekins-Daukes3 and M. A. Malik (2003),
Quantum Dot Solar Concentrator, Proceedings of Symposium on the Efficient Use of Solar
Radiation in Photovoltaics Power Engineering, St. Petersburg, USA, 2003.
J.A. Manrique (1984), A Compound Parabolic Concentrator, International Communications in
Heat and Mass Transfer, 11: 267-273, 1984.
T. Nordmann and L.Clavadetscher (2003), Understanding Temperature Effects on PV
System Performance, Proceedings of the 3rd World Conference on Photovoltaic Energy
Conversion, Osaka, Japan, 2003.
V.B. Omubo-Pepple, C. Israel-Cookey and G.I. Alaminokuma (2009), Effects of Temperature,
Solar Flux and Relative Humidity on the Efficient Conversion of Solar Energy to
Electricity, European Journal of Scientific Research, 35(2): 173-180, 2009.
W.B.
Stine
and
M.
Geyer
(2010),
Power
from
the
Sun,
Available
at
http://www.powerfromthesun.net/index.htm
Leonard D. Jaffe, Test results on parabolic dish concentrators for solar thermal power
systems, Solar Energy, Volume 42, Issue 2, 1989, pp – 173–187.
David Barley, Ruxendra Vidu, Pieter Stroeve, Innovation in concentrated solar power, Solar
Energy Materials and Solar Cells, Volume 95, Issue 10, October 2011, pp – 2703–272.
Manuel Romero, Diego Martinez, Eduardo Zarza (2004), Terrestrial Solar Power Plants : On
the verge of Commercialization, Proceedings of the 4th International Conference on Solar Power
from Space – SPS ’04.
Stine W, Diver R. B. (1994), A Compendium of Solar Dish / Sterling Technology, Report
SAND93-7026, Sandia National Laboratories, Albuquerque, New Mexico.
Becker M., Meinecke W., Geyer M., Trieb F., Blanco M., Romero M., Ferriere A. (2002), Solar35
Thermal Power Plants, Libro. The Future of Renewable Energy 2 : Prospects and Directions,
Eurec. Agency, Pub. James & James Science Publishers Ltd., London, UK, pp – 115-137, ISBN: 1902916-31-X.
REFEFENCES (CONTD.)
35.
40.
42.
43.
44.
VANITA N. THAKKAR
41.
ICORE-2013
39.
02/12/2013
36.
37.
38.
Teagan, Peter W. Review (2001), Status of Markets for Solar Thermal Power Systems,
downloadable from : http://www.energylan.sandia.gov/sunlab/pdfs/adlitt1.pdf.
Hsieh J.S. (1986), Solar Energy Engineering, Prentice-Hall, Inc., Englewood Cliffs, New Jersey.
Garg H.P. and Prakash J. (2000), Solar Energy, Tata McGraw-Hill, New Delhi.
Ibrahim Ladan Mohammed, Design and Development of a Parabolic Dish Solar Water
Heater, International Journal of Engineering Research and Applications (IJERA), Vol. 2, Issue 1,
Jan-Feb 2012, pp. 822-830
S.M. Jeter, Maximum conversion efficiency for the utilization of direct solar radiation, Sol.
Energy 26 (1981) , pp – 231-236.
W.T.T. Dayanga and K.A.I.L.W. Gamalath, Thermodynamic investigation of solar energy
conversion into work, Sri Lanka Journal of Physics, Vol. 9 (2008), pp – 47-60
Energy
and Civilization
:
Patterns
of consumption,
downloadable
from :
www2.ic.edu/beal/eschapter9pp.ppt.
United Nations Industrial Development Organization, Renewable Energy in Industrial
Applications : An assessment of the 2050 potential, downloadable from :
http://www.unido.org/fileadmin/user_media/Services/Energy_and_Climate_Change/Energy_Efficienc
y/Renewables_%20Industrial_%20Applications.pdf.
Binay Kumar Ray and B. Sudhakara Reddy (2008), Understanding industrial energy use:
Physical energy intensity changes in Indian manufacturing sector, downloadable from :
www.eaber.org/sites/default/files/documents/IGIDR_Ray_2008.pdf.
PricewaterhouseCoopers P Limited, India for Deutsche Gesellschaft für Internationale
Zusammenarbeit (GIZ) GmbH (2011), Identification of Industrial Sectors Promising for
36
Commercialisation of Solar Energy, downloadable from : http://www.giz.de/Themen/de/SID172ACBDB-8E15AA1F/dokumente/giz2011-commercialisation-solar-energy-india-en.pdf.
REFEFENCES (CONTD.)
ICORE-2013
VANITA N. THAKKAR
53.Paul A. Funk: Evaluating the international standard procedure for testing solar cookers and
reporting performance.: Pergamon PI I : S0038 – 092X(99)00059 – 6, Solar Energy Vol. 68, No. 1,
pp. 1–7, 2000, Published by Elsevier Science Ltd.
54.Subodh Kumar : Estimation of design parameters for thermal performance evaluation of boxtype solar cooker : Renewable Energy 30 (2005) 1117–1126
02/12/2013
45.Dr. Shireesh B. Kedare, Solar Thermal Applications for Industrial Process Heat (IPH),
downloadable from : www.ese.iitb.ac.in/events/other/concentrator_workshop/profile.PDF.
46.Deepak Gadhia, Parabolic Solar Concentrators for Cooking and Food Processing, International
Solar Food Processing Conference 2009.
47.Briefing given at : http://www.greenashram.org/solarenergy.
48.Atul Sagade, Nilkanth Shinde, Performance evaluation of parabolic dish type solar collector
for industrial heating application, International Journal of Energy Technology and Policy, 2012
Vol.8, No.1, pp.80 – 93.
49.Details available from : www.clique.in/ARUN PROFILE.pdf
50.M. Eswaramoorthy; S. Shanmugam, The Thermal Performance of a Low Cost Solar Parabolic
Dish Collector for Process Heat, Energy Sources: Recovery, Utilization, and Environmental
Effects Vol.: 34, No.: 18, July, 10 2012, pp – 1731-1736.
51.Ajay Chandak, Sunil K. Somani, Patil Milind Suryaji, Comparative Analysis of SK-14 and
PRINCE-15 Solar Concentrators, Proceedings of the World Congress on Engineering 2011 Vol III
WCE 2011, July 6 - 8, 2011, London, U.K. pp – 1949-1951.
52.Mullick S.C., Kandpal T.C. and Subhod Kumar (1991), Thermal test procedure for a paraboloid
concentrator solar cooker, Solar energy, 46 (1991), pp – 139-144.
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-
VANITA N. THAKKAR
vanitaa.thakkar@gmail.com
VANITA N. THAKKAR
-
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THANK YOU !!
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