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Homework: How much energy does Harvard use to do “X”?. Problem statement – what is “X”? Clearly define scope/scale (room, building, campus; day, week, year; one vehicle vs. whole fleet, etc.) What do you need to know to solve the problem? Gather information and cite sources
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Homework: How much energy does Harvard use to do “X”? • Problem statement – what is “X”? • Clearly define scope/scale (room, building, campus; day, week, year; one vehicle vs. whole fleet, etc.) • What do you need to know to solve the problem? • Gather information and cite sources • Quantitative analysis – give a final answer with relevant units and convert to CO2 equivalent • Explicitly state any assumptions! • Goals: Learn to use Powerpoint to prepare slides, gain experience in giving presentations, and become familiar with energy use calculations. Ben Finio – ES 96
Example 1: Hemenway Gym TVs • Question: how much energy do all the TVs in Hemenway Gymnasium use in one day? (assume typical weekday) • Need to know to solve the problem: • # of TVs in Hemenway • Individual TV power rating • Gym operating hours • % of equipment in use throughout the day Ben Finio – ES 96
Example 1: Hemenway Gym TVs • Information: • 46 TV’s (went to the gym and counted) • Individual TV: 12V, 3A voltage and current rating (read panel on the back of the TV) • P = IV = 12V*3A = 36W • Weekday operating hours: 6 AM – 11 PM (sign on front door) • Usage throughout the day (assumption) • Solution: (5 TVs*1 hr + 10 TVs*1hr + …) * 36 W/TV = 16.6 kWh • Worst case: 46 TVs * 17 hours * 36 W/TV = 28.2 kWh Ben Finio – ES 96
Example 2: Shuttle Fuel Consumption • How much fuel does one shuttle bus use on the Quad Express route in one day? (assume typical weekday) • Need to know: • Length of route • # of runs per day • Vehicle engine type and fuel economy Ben Finio – ES 96
Example 2: Shuttle Fuel Consumption • Information: • Route from http://shuttle.harvard.edu/ • Route length from www.mapmyrun.com (2.43 mi) • Shuttles depart every 10 minutes from 7:40 AM to 4:30 PM1 • Two shuttles running at a time (assumed from live tracking) • Fuel economy 4 mpg2 (assume diesel engine) Solution: One run every 20 minutes for ~9 hrs = 27 runs (27 runs * 2.43 mi/run)/(4 mi/gal) = 16.4 gallons [1] http://www.uos.harvard.edu/transportation/passenger_transport_services/ [2] http://www.afdc.energy.gov/afdc/pdfs/mod09a_introcost.pdf Ben Finio – ES 96
Compare MTCDE’s • MTCDE: Metric Tons of Carbon Dioxide Equivalent • Conversion factors1: • Electricity: .00042 MTCDE/kWh • B20 Biodiesel: .0094 MTCDE/gal • Hemenway TVs: • 16.6 kWh * .00042 MTCDE/kWh = .007MTCDE • Shuttle bus: • 16.4 gal * .0094 MTCDE/gal = .1542MTCDE [1] Quantifying Harvard’s Greenhouse Gas Emissions, FY07 Update Ben Finio – ES 96
ES 96 Homework #1 • Assignment • Pick a topic – “How much energy does Harvard use to ______” • Clearly state problem and what you need to know to solve it • Present all information with sources • Do the math: give quantitative answer in relevant units AND convert to MTCDE • Make it interesting, not “How much power does my 75 W light bulb use?” • Details: • Sign up for a topic by 5 PM Friday (sign up sheet posted outside Pierce 318). • Email two Powerpoint slides to bfinio@fas.harvard.edu no later than 8:00 AM, Monday Feb. 2nd • Please use your last name as the beginning of the file name – e.g. “Finio_ES96hw1”, and put your name on your slides. • You will have two minutes to present your problem in class on Monday • Resources – go to course website (http://isites.harvard.edu/k54243 ), click “Library Resources” then “Engineering Sciences 96 (Spring 2009) - Research Toolkit”. • Some additional ideas: power consumption by a cluster of computers, energy required to heat a dorm room, energy required to cook a meal, energy used by stage lights in a theater performance… Ben Finio – ES 96
