CBE 555 Matt Zauner Geological Engineering Major

 Production of Light  Introduction of Lighting Technologies ◦ Incandescent Light Bulbs ◦ Compact Fluorescent Lamp (CFL) Light Bulbs ◦ Light-Emitting Diode (LED) Light Bulbs  Comparisons ◦ Energy ◦ Price ◦ Environmental  Controversy  Conclusion

 An atom contains electrons that circle the nucleus in orbitals  When an electron moves from a higher orbital to a lower orbital energy is released as light in the form of a photon  The distance of the orbital change controls the frequency  Each light technology does this differently

 Traditional Light Bulb  Uses ◦ Interior Lighting ◦ Exterior Lighting ◦ Car headlights ◦ Flashlights

 Incandescence: Emission of light by heating a filament ◦ 4000°F  Filament typically made of Tungsten  Surrounded by glass enclosing Argon gas to inhibit Combustion

 Has a lot of wasted energy which is released a heat  10% of light is in visible spectrum ◦ 90% Infrared (>700nm)

 In production for 136 years ◦  Easy to produce ◦ Use cheap materials  Short life: 1,000 hours

 Mini fluorescent tube lamp  Uses ◦ Indoor Lighting ◦ Outdoor lighting

 Gas vapor excited by electric current creating UV light which in turn stimulates fluorescent coating on inside of tube  Gas: Argon and Mercury ◦ Mercury converts to UV ◦ ounces  Fluorescent coating (phosphor) composition varies for light color

 Integrated Ballast ◦ Regulates electric current  Gives high voltage initially to produce arc  Reduces voltage and regulates current to maintain steady light output

 Almost all light produced is within visible spectrum ◦ Less light energy lost as heat  Use about 78% less energy than incandescent bulb

 More expensive than incandescent ◦ Energy rebates ◦ Becoming more standard  Saves money on energy due to lower wattage  Longer Life: 10,000 hours

 Contains Mercury Vapor ◦ Toxic metal ◦ Ounces  Circuit board and ballast contain ◦ Toxic amounts of Pb, Cu and Zn  Needs to be properly disposed of ◦ Stores have recycling stations ◦ i.e. Home Depot and IKEA  Reduces CO2 emissions  Reduced waste: longer life

 Two categories of use: ◦ Indication: light viewed as self luminous object  LED signs  Indicator lights in cars, phones, etc.  Modern TV’s or jumbotron screens ◦ Illumination: light used to view other objects by reflecting light off that object  Interior and Exterior Lighting  Car headlights  Flashlights

 Semiconducting diode used to emit light ◦ Semiconductor  P side (+)  N Side (-)  PN junction (=)  Charges in P and N sides are repelled towards PN junction  Electron falls into “hole” at PN junction ◦ Drops through an orbital ◦ Releases energy in photon form InGaN-Indium Gallium Nitride

 LED light is completely within visible spectrum ◦ Very little wasted light energy ◦ ≃85% less energy used than incandescent bulbs

 Cons: ◦ Numerous components ◦ Relatively young technology  Pros ◦ In store rebates available ◦ Saves energy ◦ Has very long life:25, ,000 hours

 Contain toxic amounts of copper ◦ Circuit board and driver  Reduce CO2 emissions  Reduced waste due to longer life

 TTLC: Total Threshold Limit Concentration ◦ California’s method to determines if item is considered hazardous waste for disposal  Consider lifetime ◦ 1,000: Incandescent ◦ 10,000: CFL ◦ 25,000-50,000: LED

 Why are these technologies being implemented at a faster pace? ◦ Too expensive  False: Much cheaper over lifetime ◦ Gives off weird colored light (bluish tint)  False: was true in past but with increased technology the colors can be matched exactly, in both LED and CFL ◦ Toxic to environment due to the use of high concentrations of metals (Pb, Hg, Zn, Cu)  False: Per lightbulb yes, but less lightbulbs needed over lifetime and proper diposal will mitigate these effects.

 Harris, Tom. "How Light Bulbs Work" 19 February HowStuffWorks.com. 20 April  Harris, Tom, and Wesley Fenlon. "How Light Emitting Diodes Work" 31 January HowStuffWorks.com. 20 April  Harris, William. "How CFL Bulbs Work" 14 July HowStuffWorks.com. 20 April  Harris, William, and Craig Freudenrich, Ph.D.. "How Light Works" 10 July HowStuffWorks.com. 20 April  Institute, R. P. (2003). LED Lighting Systems. Lighting Answers, 7(3). Retrieved from Lighting Research Institute website:  Lim, S.-R., Kang, D., Ogunseitan, O. A., & Schoenung, J. M. (2013). Potential Environmental Impacts from the Metals in Incandescent, Compact Fluorescent Lamp (CFL), and Light-Emitting Diode (LED) Bulbs. Environmental Science & Technology, 47(2), doi: /es302886m  Menards, “Light Bulbs” menards.com 20 April 2015.