Design of Solar Lighting System for Energy Saving

Irfan Ullah Department of Information and Communication Engineering Myongji university, Yongin, South Korea

International Conference on Modeling and Simulation 2013

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Contents

1. Introduction2. Objective3. Background4. Design of the proposed system5. Light transmission through optical fibers6. Simulation and results7. Conclusions and Future Work

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• 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)

Introduction

Top 10 emitting countries in 2009, IEA 2011Energy supply USA, EIA Annual Energy Review 20092/21

• 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

Introduction

Residential end-use energy consumption, WBCSD 20093/21

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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Sunlight directFiber optic mini dish system

Background

• Sunlight transmission through optical fibers using• Parabolic reflector and Fresnel lens

• Non-uniform illumination

Himawari solar lighting system

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Background - Nonuniformity

Parabolic reflector with Flat reflector

Parabolic reflector withHyperbola reflector

Fresnel lens

Non-uniform Non-uniform Low illuminance6/21

Background

• Hybrid daylighting systems• Beam splitter• Costly• Non-uniformity

Hybrid daylighting system (lighting + photovoltaic)

Hybrid lighting and photovoltaic)To use low efficient concentrated PV area for daylight

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Our previous hardware design

Setup of the sunlight collecting system

• Uniform illumination

• Difficult to arrange 2nd reflector

• Issue of shadow due to 2nd reflector• Reduces illuminance

Journal of the Optical Society of Korea 16(3), 247-255 (2012) 8/21

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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Design of the daylighting system

Design using parabolic reflector

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Light Transmission

• 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

Optical fibers with index matchingOptical fiber bundle

ncladding = 1.40ncore = 1.457

ncladding = 1.40ncore = 1.49

Refractive index

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54 fibers

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 fibers12/21

Simulation

Candle power distribution curveUniform illumination over fiber bundle

• Daylighting simulation• LightTools®, DIALuxTM, and SolidWorksTM

• Uniform illumination into each optical fiber

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Interior view

Floor plan of test room

• 6 bundles of optical fibers• 6 LED light sources

Section view of room’s interior14/21

Indoor illuminance distribution

Daylight distribution on working plan

dS : Surface areadF : Luminus flux on the surface

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Illuminance (lx)

Indoor illuminance

Indoor illuminance distribution

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Indoor lighting simulation

Hybrid daylighting system

• LED light• OSRAMTM LW-W5AM, 130 lm/W• 26 LEDS with one reflector • Achieving illuminance of 500 lx at all times

LEDs with parabolic reflector

Arrangement of LEDs

Illuminance on working plane17/21

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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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)19/21

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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References

1. I. Ullah and S. Shin, “Development of Optical Fiber-Based Daylighting System with Uniform Illumination,” J. Opt. Soc. Korea 16, 247-255 (2012).

2. I. Ullah and S. Shin, "Uniformly Illuminated Efficient Daylighting System," Smart Grid and Renewable Energy, Vol. 4, No. 2, pp. 161-166 (2013).

3. 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).

4. V. E. Gilmore, “Sun flower over Tokyo,” Popular Science, Bonnier Corporation, America, 1988.

5. D. Feuermann, J. M. Gordon, “SOLAR FIBER-OPTIC MINI-DISHES: A NEW APPROACH TO THE EFFICIENT COLLECTION OF SUNLIGHT,” Sol. Energy. 65, 159-170 (1999).

6. D. Feuermann, J. M. Gordon, M. Huleihil, “Solar fiber-optic mini-dish concentrators: first experimental results and field experience,” Sol. Energy. 72, 459-472 (2002).

7. A. Kribus, O. Zik, J. Karni, “Optical fibers and solar power generation,” Sol. Energy. 68, 405-416 (2000).

8. C. Kandilli and K. Ulgen, “Review and modelling the systems of transmission concentrated solar energy via optical fibres,” Renewable and Sustainable Energy Reviews, 13, 67-84 (2009).

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Irfan UllahDept. of Info. and Comm. EngineeringMyongji University, Yongin, South KoreaEmail: irfan@mju.ac.krHomepage: sl.avouch.org

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