1/29/09Ben Finio – ES 961 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 CO 2 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.

1/29/09Ben Finio – ES 962 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

1/29/09Ben Finio – ES 963 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

1/29/09Ben Finio – ES 964 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

1/29/09Ben Finio – ES 965 Example 2: Shuttle Fuel Consumption Information: –Route from –Route length from (2.43 mi) –Shuttles depart every 10 minutes from 7:40 AM to 4:30 PM 1 –Two shuttles running at a time (assumed from live tracking) –Fuel economy 4 mpg 2 (assume diesel engine) [1] [2] Solution: One run every 20 minutes for ~9 hrs = 27 runs (27 runs * 2.43 mi/run)/(4 mi/gal) = 16.4 gallons

1/29/09Ben Finio – ES 966 Compare MTCDE’s MTCDE: Metric Tons of Carbon Dioxide Equivalent Conversion factors 1 : –Electricity: MTCDE/kWh –B20 Biodiesel:.0094 MTCDE/gal Hemenway TVs: –16.6 kWh * MTCDE/kWh =.007 MTCDE Shuttle bus: –16.4 gal *.0094 MTCDE/gal =.1542 MTCDE [1] Quantifying Harvard’s Greenhouse Gas Emissions, FY07 Update

1/29/09Ben Finio – ES 967 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). – two Powerpoint slides to no later than 8:00 AM, Monday Feb. 2 –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 ( ), 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…