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

Contents Introduction Objective Background Design of the proposed system Light transmission through optical fibers Simulation and results Conclusions and Future Work 1/21

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 2/21

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 3/21

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 4/21

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 5/21

Background - Nonuniformity Parabolic reflector with Flat reflector Parabolic reflector with Hyperbola reflector Fresnel lens Non-uniform Non-uniform Low illuminance 6/21

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) 7/21

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), 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 9/21

Design of the daylighting system Design using parabolic reflector 10/21

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 11/21

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 12/21

Simulation Daylighting simulation LightTools®, DIALuxTM, and SolidWorksTM Uniform illumination into each optical fiber Uniform illumination over fiber bundle Candle power distribution curve 13/21

Interior view 6 bundles of optical fibers 6 LED light sources Section view of room’s interior Floor plan of test room 14/21

Indoor illuminance distribution Illuminance (lx) dS : Surface area dF : Luminus flux on the surface Indoor illuminance Daylight distribution on working plan 15/21

Indoor illuminance distribution Indoor lighting simulation 16/21

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 17/21

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 18/21

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 20/21

References I. Ullah and S. Shin, “Development of Optical Fiber-Based Daylighting System with Uniform Illumination,” J. Opt. Soc. Korea 16, 247-255 (2012). I. Ullah and S. Shin, "Uniformly Illuminated Efficient Daylighting System," Smart Grid and Renewable Energy, Vol. 4, No. 2, pp. 161-166 (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, 159-170 (1999). 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). A. Kribus, O. Zik, J. Karni, “Optical fibers and solar power generation,” Sol. Energy. 68, 405-416 (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, 67-84 (2009). 21/21

Discussion Irfan Ullah Dept. of Info. and Comm. Engineering Myongji University, Yongin, South Korea Email: irfan@mju.ac.kr Homepage: sl.avouch.org