1 / 23

True Green Lighting

True Green Lighting. Professor CHUNG, Shu-hung Henry Associate Dean, College of Science and Engineering City University of Hong Kong. Overview. Electricity consumption Efficacy of light sources How eyes work Characteristics of different lamps Cost estimation Energy saving solution

abrodie
Download Presentation

True Green Lighting

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. True Green Lighting Professor CHUNG, Shu-hung Henry Associate Dean, College of Science and Engineering City University of Hong Kong

  2. Overview • Electricity consumption • Efficacy of light sources • How eyes work • Characteristics of different lamps • Cost estimation • Energy saving solution • Conclusion

  3. Electricity consumption Grid-based electric lighting consume about 19% of the total global electricity consumption, 5% to 15% in industrialized countries and 86% in developing countries [1]. Global electricity consumption [1] Eino Tetri, "Concepts and techniques for energy efficient lighting solutions," Helsinki University of Technology

  4. Efficacy of light sources Source: W.P. Lapatovich, “Metal-halide lamp design: atomic and molecular data needed,” Phys. Scr. T134(2009) (Available at http://iopscience.iop.org/1402-4896/2009/T134/014024/pdf/physscr9_T134_014024.pdf)

  5. How eyes work Source: www.howard.k12.md.us/res/eyes/howeyeswork.html

  6. Spectral luminous efficacy for human vision Source: http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html

  7. Scotopic and photopic visions Source: http://www.visual-3d.com/Education/LightingLessons/Documents/PhotopicScotopiclumens_4%20_2_.pdf

  8. Metal Halide (MH) • Lifetime: 5,000 – 22,000 hours • Efficacy: 100lm/W • Color rendering index (CRI) : 90% Source:http://www.plantlightinghydroponics.com/eye-1000w-5500k-hortilux-horizontal-metal-halide-lamp-p-1873.html Source: www.archithings.com/search/osram+halogen+100w

  9. High pressure sodium (HPS) • Lifetime: 10,000 – 32,000 hours • Efficacy: 150lm/W • Color rendering index (CRI) : 22% Source: Philips SON AGRO 430W HPS Lamps Source: www.planetnatural.com/site/xdpy/kb/hps-lamps.html

  10. Fluorescent (FL) • Lifetime: 8,000 hours (drop of 10-20% light) • Efficacy: 100lm/W • Color rendering index (CRI) : 85% Source: http://www.instructables.com/image/F95AE4AFCHYO8MX/Take-apart-a-Compact-Fluorescent-Bulb.jpg Source: http://www.conservationphysics.org/intro/fundamentals.php

  11. Light Emitting Diode (LED) • Lifetime: 50,000 – 100,000 hours • Efficacy: 60lm/W • Color rendering index (CRI) : 70-80% http://www.bombayharbor.com/productImage/0452548001254038567/Amusement_Led_Lamp.jpg http://www.f3images.com/IMD/Md_images/blue_moon_aquatics_90W_LED_light_spectrum.jpg

  12. Green lighting Energy consumption Light performance Investment return Environmental aspect

  13. HPS and LED Source: http://ltiled.com/led/scotopic_vs_photopic/

  14. Energy and light

  15. Component Cost (FL and LED) Consider the lamp tubes only I. T8 FL lamp • Retail price: HK$30 II. Retrofit T8 LED lamp • Cost of one 0.1W LED: US$0.13 • Required output lumen: 1500lm • Required no. of LED: 200 • Cost of LED for one lamp: US$26 • Cost of mechanical housing: US$5 • Total cost of one LED lamp: US$31 • Retail price: US$80-90 (HK$640 – 720)

  16. Running Cost (FL and LED) Assumptions: • 12-hour service • $1.0/kWh • 5-year service I. T8 FL lamp (30W) • Power consumption in five years: 657kWh ($657) • Replacement of the lamp tube: $30 x 3 ($90) II. T8 LED lamp (20W) • Power consumption in five years: 438kWh ($438) Saving in five years: ($657 + $90 - $438) = $309

  17. Projection of the cost • LED Luminous efficiency : +10% each year • Cost : -10% each year Thus, the overall cost reduction each year: -15% each year. Projection of the cost of an LED lamp: 2010 : US$31 [HK$248] (Retail price : $640 - $720) 2011 : US$26 [HK$208] (Retail price : $536 - $604) 2012 : US$22 [HK$176] (Retail price : $454 – $511) 2013 : US$19 [HK$152] (Retail price : $392 - $441) * 2014 : US$16 [HK$130] (Retail price : $330 - $371) *

  18. Challenges of LED lamps • Color rendering index • Aging problem • Lifetime • Thermal management • Non-standard technical specifications (single supplier ?) Implications: • Is it really necessary to have a separate LED driver? • LED lamp with integrated driver • AC-powered LED

  19. How to save energy in this FL-to-LED transition era ? • Rule of thumb – reducing 1kWh consumption is easier than generating 1kWh • Wait and see the development of LED technology • Small-scale trial with low-power LED light bulbs • Can we do something to help save energy? Other: • Disposal of FL lamps (Any incentive scheme?) • Change all existing FL into LED lamps • Environmental issue • Investment $$

  20. Centralized lighting control Meter room

  21. Advantages of this concept • Suitable for MH, HPS and CFL lamps • Short payback period (about 2 years) • Immediate solution to reduce the energy consumption by 20% ($$ and CO2) • No need to change or modify existing lighting equipment and infrastructure • Optimal Lux level adjustment *Note: It is important to ensure that the voltage supplying to the lamp can be continuously adjusted. Otherwise, the lamp life will be affected.

  22. Conclusions • LED lighting will be the future, but when? • Technology, $$, eco aspects, … • Is that any available solutions that can immediately reduce energy consumption? • Any room to reduce the required luminance level, 100lux  80lux  50lux (but, we have to take care of the visually impaired people) • Is it possible to set up an incentive scheme to make the occupants dispose their CFL in an environmentally friendly way?

  23. Thank you

More Related