EIN4905 Dr. Cristi n C rdenas Lailhacar Dept. of Industrial and Systems Engineering University of Florida Thesis on high costs and waste of energy in lighting Jossie Buzaglu 3178 3651
Abstract In this article we will show some hypothesis and show how lighting is using so much energy in the University of Florida in Gainesville, FL. We will demonstrate how using energy efficient items such as CFL light bulbs, Fluorescent Lamps and movement sensors will translate into cost savings, energy sav ings and in the end helping our environment. In the case study we will show that not only in University of Florida, but how in different environments such as Industrial, Household or Retail environment there could be room for savings in energy and money. Figure 1: Incandescent light bulbs in the back, CFL light bulb in the front
Introduction As the symbol of innovation, the incandescent light bulb is not very innovative. It hasn't changed much since Thomas Edison introduced it in 1879. Even today, it still generates light by heating a tungsten filament until it reaches 4,172 degrees Fahrenheit (2,300 degrees Celsius) and glows white hot. Unfortunately, all of that white light is not very gree n. A good deal of electricity, electricity from co al fired powered plants responsible for spewing green house gases into the atmosphere is required to make an incandescent bulb burn brightly. Only 10 percent of that energy goes toward making light. The rest is wasted as heat. Luckily for our CO 2 soaked pla net, there's a new type of light bulb that stands poised to replace Edison's most famous invention as the icon of ideation. It's known as the compact fluorescent light bulb, or CFL, and its illumination comes by way of a much different mechanism. Instead o f a glowing filament, CFL s contain argon and mercury vapor housed within a spiral shaped tube. They also have an integrated ballast, which produces an electric current to pass through the vaporous mixture, exciting the gas molecules. In older CFL s, it to ok several seconds for the ballast to produce enough electricity to ramp up the excitation. Newer CFL s have more efficient ballasts and require a shorter warm up. Either way, when the gas gets excited, it produces ultraviolet light. The ultraviolet light, in turn, stimulates a fluorescent coating painted on the inside of the tube. As this coating absorbs energy, it emits visible light. In this work we will first talk about the current situation in the University of Florida, where currently there is a lot o f energy being wasted because of wrong procedure to save energy and bad planning for the lighting in the facilities. In the second section we will discuss high efficiency lighting (CFL light bulbs), how they work, their benefits and their limitations. In section three we will discuss some numbers, do some calculations, and show how just by changing from one type of light bulb to the other we can save money and energy in the end.
Current Situation The University of Florida has over 900 buildings on the mai n campus. Of these 900 buildings we can say that more than half use lighting throughout a regular class date (not to mention they leave the lights on during nighttime). Currently UF is in the LEED (Leadership in Energy and Environmental Design) Green Build ing Rating System this program is intended to promote a whole building approach to sustainability by recognizing performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials sel ection and indoor environmental quality. Even though the University of Florida is currently part of the LEED program, there are many procedures not well organized and inefficient the university follows. Going into some examples we have: when an old incand escent light bulb runs out, instead of exchanging it for a CFL efficient light bulb they change it for the incandescent type of light bulb. Another simple example is the amount of wasted energy during nighttime. Most of the buildings of the main UF campus remain with its switches on, even though there are no classes or meeting going on at those times. These policies have to change in order to have a more sustainable campus in Gainesville, Florida. The University of Florida should act as the educational inst itution it is to pursue a more sustainable campus, where they teach not only students but also the community, to reduce green house emissions, and make this world a better place.
High Efficiency Lighting escent bulbs. In an incandescent, electric current runs through a wire filament and heats the filament until it starts to glow. In a CFL, an electric current is driven through a tube containing argon and a small amount of mercury vapor. This generates invi sible ultraviolet light that excites a fluorescent coating (called phosphor) on the inside of the tube, which then emits visible light. CFLs need a little more energy when they are first turned on, but once the electricity starts moving, use about 75% less energy than incandescent bulbs. A CFL's ballast (the electronic part that regulates the electric current through a fluorescent lamp) helps "kick start" the CFL and then regulates the current once the electricity starts flowing. Figure 2: Detailed side vie w of a CFL with its parts CFL Lighting Benefits Efficient: CFL s are four times more efficient and last up to 10 times longer than incandescents. A 22 watt CFL has about the same light output as a 100 watt incandescent. CFL s use 50 80% less energy than incandescents. Less Expensive: Although initially more expensive, you save money in the long run because CFLs use 1/3 the electricity and last up to 10 times as long as incandescents. A single 18 watt CFL used in place of a 75 watt incandescent will save about 570 kWh over its lifetime. At 8 cents per kWh, that equates to a $45 savings. Reduces Air and Water Pollution: Replacing a single incandescent bulb with a CFL will keep a half ton of CO2 out of the atmosphere over the life of the bulb. If
everyone in the U.S. used energy efficient lighting, we could retire 90 average size power plants. Saving electricity reduces CO2 emissions, sulfur oxid e and high level nuclear waste. High Quality Light: Newer CFL s give a warm, inviting light instead of the "cool white" light of older fluorescents. They use rare earth phosphors for excellent color and warmth. New electronically balla Versatile: CFL s can be applied nearly anywhere that incandescent lights are used. Energy efficient CFLs can be used in recessed fixtures, table lamps, track lighting, ceiling fixtures and porchlights. 3 way CFL s are also now available for lamps with 3 way settings. Dimmable CFL s are also available for lights using a dimmer switch. Figure 3: Table with difference in energy used, mercury emissions and environmental impact of the two light bulbs Limitations of CFL lightbulbs Although CFLs are an excellent source of energy efficient lighting, they are not always the best choice for all ligh ting applications. Here are a few limitations to consider:
On/Off cycling: CFL s are sensitive to frequent on/off cycling. Their rated lifetimes of 10,000 hours are reduced in applications where the light is switched on and off very often. Closets and ot her places where lights are needed for brief illumination should use incandescent or LED bulbs. Dimmers: Dimmable CFL s are available for lights using a dimmer switch, but check the package; not all CFL s can be used on dimmer switches. Using a regular CF L with a dimmer can shorten the bulb life span. Timers: Most CFL s can be used with a timer, however some timers have parts which are incompatible with CFL s; to check your timer, consult the timer package or manufacturer. Using an incompatible timer can shorten the life of a CFL bulb. Outdoors: CFL s can be used outdoors, but should be covered or shaded from the elements. Low temperatures may reduce light levels check the package label to see if the bulb is suited for outdoor use. Retail lighting: C FL s are not spot lights. Retail store display lighting usually requires narrow focus beams for stronger spot lighting. CFL s are better for area lighting. Mercury content: CFL s contain small amounts of mercury which is a toxic metal. This metal may be r eleased if the bulb is broken, or during disposal.
Mercury Content Disposal Bulb Eater A Bulb Eater is a lamp crushing machine that processes, or crushes, spent fluorescent lamps into small fragments. The crushed glass is compacted into 55 gallon c ontainers. The machine not only crushes straight fluorescent lamps of any length, but also u shaped fluorescent lamps as well. This greatly improves storage of the lamps, handling, safety/liability issues, and recycling costs. How does the Bulb Eater work ? 1. The lamp is fed into the entry tube of the machine. 2. In roughly one second the lamp, whether straight or u tube enters the machine and is crushed to pieces. 3. filter out the re leased powder as well the mercury vapor. 4. The contaminated air goes through a two stage filtering process in the blue case. The first stage filter captures over 99% of the released dust particulate. The second stage HEPA filter acts as a polishing filter an d captures over 99.99% of the remaining particulate. 5. At that point the air is clean but still contains mercury vapor. 6. The mercury vapor is then blown out of the blue case and through the third and final filter. 7. The carbon filter not only captures the merc ury vapor, but also neutralizes it by converting the vapor to mercuric sulfide, which is non hazardous. 8. Clean air comes out of the Bulb Eater exhaust vent. Figure 4: Image of a light bulb eater
Demand and energy savings Economic Analysis Case Study: Lets explore a scenario where we compare a 1,000 Watt MH incandescent light bulb and a 200 compact flu orescent lamp (CFL). These two light bulbs emit about the same amount of luminescence. DEMAND REDUCTION (DR): DR=(N*KW MH *BF MH ) (N*KW CFL *BF CFL ) Where: N =number of lamps W =Energy BF =Ballast Factor. So, DR=10[(.40KW*1.15) (0.15KW*0.9)] DR= 3.25 KW ENERGY SAVI NGS (ES): ES=DR*H Where: DR =Demand Reduction H =Hours in a year ES=3.25KW*8,760H/Year ES=28,470 KWh/Year LAMP FACTOR (LF): It tells us whether a given lamp should be replaced by ratio number of lamps. LF=Avg. Life hours of current lamp/Avg. Life hours of pro posed lamp LF=20,000/8,000=2.5
COST SAVINGS (CS): Total savings in dollars per year Assuming: Cost of Demand=$8/KWmonth Cost of energy=$0.06/KWhour CS=Demand Savings+Energy Savings CS=(3.25KW*$8/KWMonth*12month/year)+(2,847KWhours/year*$0.06/KWhours) CS =$979.2/yr+$5361/yr CS=$2,020.2/yr Implementation Cost: Cost incurred including lamp value and labor cost. IC=(Lamp Cost*Lamp Factor)+(Labor*Lamp Factor) IC=(Lamp Cost+Labor)*LF*Number of Lamps IC=[$50/Lamp+($15/hr*1hr/60min*10min/1lamp)]*2.5*10 lamps IC=$ 1 312.5 Simple Payback Period (SPP): Is the amount of time in which you receive the breakeven value of the initial investment. SPP=IC/CS SPP=$1312.5/$2,020.2/yr SPP= 0.65 years
Overall Calculations and Tables for economic analysis Here are some table s showing the savings using the calculations shown before. The first table (yellow and green) shows the current lighting numbers with which we made the calculations. The second table (pink) shows the numbers that the proposed lighting would have. After tha t we have a couple of tables that shows the assumptions we make such as the hours in a year or the dollars per KWh that is charged by the electric company on average. Then we have a table with the values obtained as saving for delta KW, energy savings, lam ps factor (LF), Cost Saving (CS), Implementation Cost (IC) and Simple Payback Period (SPP). Current Lighting Type Number of Lamps Watts Ballast Factor Avg. Life Hours Price per lamp Retail Fluorescent Lamp 10 40 1 20000 $17 Industry Metal Halid e 10 400 1.15 20000 $190 Household Fluorescent Lamp 10 60 1 8000 $13 New Proposed Lighting Type Number of Lamps Watts Ballast Factor Avg. Life Hours Price per lamp Fluorescent Lamp 10 32 0.9 29000 $11.01 CFL 10 150 0.9 8000 $50 CFL 10 13 0.9 12000 $6.44 Assuming for Industry $8 Kw/month 0.06 $/kwH Assuming for Commercial $0.90 $/kwh Assuming for Household 1.1 $/kwH Assumed Labor Cost $15
Delta KW (KW) Energy S avings (KWh/Year) Lamps Factor (LF) Cost Savings (CS) Implementation Cost (IC) Simple Payback Period (SPP) 0.112 981.12 0. 69 $893.76 $93.17 0. 104 3.25 28470 2.5 $2,020.20 $1,250.00 0. 62 0.483 4231.08 0.67 $4,700.56 $42.93 0.0091 After these calc ulations, it was decided to show what would be the Delta KW/$ of savings depending on the number of lamps, to show these calculations we decided to do it for 1 lamp, 5 lamps, 10, 50 and 100 lamps. And this was shown for the three cases (Industrial Environm ent, Household Environment and Retail Environment). Industry Number of Lamps Delta KW/ $ 1 325 5 1625 10 3250 50 16250 100 32500 Household Number of Lamps Delta KW/ $ 1 48.3 5 241.5 10 483 50 2415 100 4830 Retail Number of Lamps Delt a KW/ $ 1 11.2 5 56 10 112 50 560 100 1120 Hours per year 8760 Months in a year 12
Concl usions After carefully studying the possible substitutions for incandescent or metal halide lighting, and also analyzing the different savings with respect to the amount of lamps to be changed, it is clear that changing to the light bulbs containing but also this type of light bulbs translate into energy savings, that will help lower the electric bill and help the envi ronment in the long run.
References http://www.eartheasy.com/live_energyeff_lighting.htm http://energystar.custhelp.com/cgi bin/energystar.cfg/php/enduser/std_adp.php?p_faqid=5527&p_created=1230916363 http://www.facilities.ufl.edu/sustain http://www.aircycle.com/resources/articles/crushing fluorescent bulbs saving the environment while saving money.aspx