1. Design of Solar Lighting System for Energy Saving
Irfan Ullah
Department of Information and Communication Engineering Myongji university, Yongin, South Korea
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International Conference on Modeling and Simulation 2013

2. Contents Introduction Objective Background
Design of the proposed system
Light transmission through optical fibers
Simulation and results
Conclusions and Future Work
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3. Introduction Energy consumption
In USA, 40.4% of total energy is used in buildings (EIA 2012)
In South Korea, 46% of total energy is consumed in buildings (EIA 2007)
Energy supply USA, EIA Annual Energy Review 2009
Top 10 emitting countries in 2009, IEA 2011
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4. Residential end-use energy consumption, WBCSD 2009
Introduction
Energy use by residential buildings vary significantly by region
Lighting is a major source of energy consumption in buildings
Saving electric lighting energy consumption is one of the objectives of sustainable buildings
Residential end-use energy consumption, WBCSD 2009
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5. Daylighting Daylight provides healthy environment
Daylighting illuminates interior
Daylighting system (active and passive)
Capturing and delivering daylight
Hybrid daylighting system
Daylight + Artificial light
“Daylight building can reduce electric lighting energy
consumption by 50–80%” (U.S. Green Building Council)
Overview of daylighting
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6. Background Sunlight transmission through optical fibers using
Parabolic reflector and Fresnel lens
Non-uniform illumination
Himawari solar lighting system
Fiber optic mini dish system
Sunlight direct
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7. Background - Nonuniformity
Parabolic reflector with
Flat reflector
Parabolic reflector with
Hyperbola reflector
Fresnel lens
Non-uniform
Non-uniform
Low illuminance
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8. Background Hybrid daylighting systems Beam splitter Costly
Non-uniformity
To use low efficient concentrated PV area for daylight
Hybrid lighting and photovoltaic)
Hybrid daylighting system (lighting + photovoltaic)
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9. Our previous hardware design
Uniform illumination
Difficult to arrange 2nd reflector
Issue of shadow due to 2nd reflector
Reduces illuminance
Setup of the sunlight collecting system
Journal of the Optical Society of Korea 16(3), (2012)
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10. Objective Concentration of sunlight through
Parabolic reflector
Collimated light for optical fibers
Uniform illumination at
Capturing stage
Distribution stage
Use of low cost plastic optical fiber
Reducing CO2 emission
Parabolic reflector
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11. Design of the daylighting system
Design using parabolic reflector
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12. Light Transmission Area of the room = 16x4 m
Refractive index
Area of the room = 16x4 m
Silica optical fiber (SOF)
Length of single SOF = 130 mm
Plastic optical fiber (POF)
Length of single POF = 10 m
ncladding = 1.40
ncore = 1.49
ncladding = 1.40
ncore = 1.457
54 fibers
Optical fibers with index matching
Optical fiber bundle
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13. Behavior of the incident light on the diffuser lens
Light Distribution
One bundle: 19 optical fibers
Illumination area for one bundle = 16x4 m
Light distribution
Biconcave lens and concavo convex lens
Focal length of the lens
r1 and r2 are radii
n is refractive index,
which is 1.459
Behavior of the incident light on the diffuser lens
Bundle of optical fibers
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14. Simulation Daylighting simulation
LightTools®, DIALuxTM, and SolidWorksTM
Uniform illumination into each optical fiber
Uniform illumination over fiber bundle
Candle power distribution curve
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15. Interior view 6 bundles of optical fibers 6 LED light sources
Section view of room’s interior
Floor plan of test room
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16. Indoor illuminance distribution
Illuminance (lx)
dS : Surface area
dF : Luminus flux on the surface
Indoor illuminance
Daylight distribution on working plan
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17. Indoor illuminance distribution
Indoor lighting simulation
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18. Hybrid daylighting system
LED light
OSRAMTM LW-W5AM, 130 lm/W
26 LEDS with one reflector
Achieving illuminance of 500 lx at all times
Arrangement of LEDs
LEDs with parabolic reflector
Illuminance on working plane
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19. Economics Cost of parabolic reflector = $200
Cost of tracking modules = $200
Total optical fibers = 54
Total length of SOF = 16.2 m
Cost of SOF = $1.2/m
Total cost of SOFs = $ 19.44
Total length of POF = 10 m
Cost of POF = $0.514/m
Total cost of POFs = $ 278
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20. Conclusions
Fiber-based daylighting system can be used to illuminate office buildings uniformly
Possible to insert uniform light into each optical fiber
Heat problem is reduced
Achieving more than 500 lx at all times
Hybrid system by combining LED light and daylight
Better illumination levels
Save more than 40% electric lighting energy consumption in buildings
Low-cost system (using POFs)
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21. Future work Integrating solar cells with the system
Producing electricity by solar cells when daylight is not needed
Use of transmission media (light pipe or optical fiber) to transmit light at long distance
Should be low-cost
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22. References
I. Ullah and S. Shin, “Development of Optical Fiber-Based Daylighting System with Uniform Illumination,” J. Opt. Soc. Korea 16, (2012).
I. Ullah and S. Shin, "Uniformly Illuminated Efficient Daylighting System," Smart Grid and Renewable Energy, Vol. 4, No. 2, pp (2013).
C. Tsuei, W. Sun, and C. Kuo, “Hybrid sunlight/LED illumination and renewable solar energy saving concepts for indoor lighting,” Opt. Express 18, A640-A653 (2010).
V. E. Gilmore, “Sun flower over Tokyo,” Popular Science, Bonnier Corporation, America, 1988.
D. Feuermann, J. M. Gordon, “SOLAR FIBER-OPTIC MINI-DISHES: A NEW APPROACH TO THE EFFICIENT COLLECTION OF SUNLIGHT,” Sol. Energy. 65, (1999).
D. Feuermann, J. M. Gordon, M. Huleihil, “Solar fiber-optic mini-dish concentrators: first experimental results and field experience,” Sol. Energy. 72, (2002).
A. Kribus, O. Zik, J. Karni, “Optical fibers and solar power generation,” Sol. Energy. 68, (2000).
C. Kandilli and K. Ulgen, “Review and modelling the systems of transmission concentrated solar energy via optical fibres,” Renewable and Sustainable Energy Reviews, 13, (2009).
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23. Discussion Irfan Ullah Dept. of Info. and Comm. Engineering
Myongji University, Yongin, South Korea
Homepage: sl.avouch.org