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Name  Appliance  Energy Consumption (J/year)  Number on Campus  Total Energy  

example  microwave  3.73 * 10^4 kJ/year  1077.1  4.01 * 10^7 kJ  
Sarah  Cell chargers 

 1.45 *10^7 J/year  1764  2.56 *10^7kJ  
Andy  Laptop chargers 

 4.60 E8 J/year  1867  8.59 E8 kJ  
Reuben  Televisions 

 99600kj/femaleyr; 24300kj/maleyr  960 female; 790 male  2.88 E8 kJ/yr  
Erin  Hair Straighteners 

 1.96 * 10^7 J/year  966.7  3.45 *10^7 kJ  
Rachael  Alarm Clocks 

 Lamps  9.58 E7 J/yr  1717  1.65 E8 kJ 
Amy  Refrigerators 

 2.7 * 10^8 J/year  600  1.62 * 10^9 kJ  
Devon  Speakers 

 6.93 * 10^7 J/year  1235  8.56 * 10^7 kJ  
Mike  Electric Razors 


 1.79 * 10^3 J/year  706  1.26 * 10^5 kJ 
Kimberly  clocks  1.36 x 10^8 J/yr  752  2.4 x 10^8 kJ/yr  
Greg  Coffee Maker  1.281 x 10^5 kJ/year  176.4  2.260 x 10^7 kJ/yr  
Josie  Microwave  5.3 * 10^5 kJ/year  875  4.6 * 10^8 kJ  
Trevor  Gaming Console 

 total 

Once you have selected the appliance, survey 10 or more rooms to get a statistical sampling of the appliance frequency on campus. Determine the energy consumed by the appliance over the course of the academic year and compute the total energy consumed by all students using the appliance. Put your data in the table above and provide the details on your appliance and your calculations below. This assignment is only submitted on this page.
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Electric Razors
Sample #  Brand  Use (min/week)  Voltage (J/c)  Current (c/sec)  Power (J/sec) 

1  Braun  10  12  0.400  4.8 
2  Braun  12  12  0.400  4.8 
3  No Razor 




2 4  No Razor 




5  No Razor 




6  Phillips Norelco  7  15  0.420  6.3 
7  Phillips Norelco  12  15  0.420  6.3 
8  No razor 




9  No razor 




10  No razor 




Average  40% of student body  10.25 

 5.6 
Average Energy Consumption:
5.6 J/sec * 60 sec/min * 10.25 min/week * 52 weeks/year = 1.79 * 10^3 J/year
Assuming only males use electric shavers
1.79 * 10^3 J/razor/year * 1764 students * 0.40 razors/student * 1J/1000kJ = 1.26 * 10^5 kJ/year
Devon McIntyre, iPod/Computer Speakers
Sample #  Brand  Voltage (V)  Current (A)  Power (W) 

1  Altec Lansing,  100  240  0.8  80 
2  Logitech  120  0.525  63 
3  Bose  120  0.16  19.2 
4  Bose  120  0.16  19.2 
5  JBL  120  0.183  22 
6  JBL  120  0.183  22 
7  JBL  120  0.183  22 
8  Klipsch  100  240  max 1.5  150 
9  iSymphony  120  0.9  108 
10  JBL  120  0.183  22 
Average 


 52.74 
Average energy consumption in a year assuming speakers are used 1 hour per day:
52.74 J/sec * 60 sec/1 min * 60 min/1 day * 365 days/1 year = 6.93 E7 J/year
Colby students total – 1838
% Colby students on campus – 96%
Total Colby students on campus – 1764
Assume 70% of students have speakers – 1764 * .70 = 1235 students with speakers on campus
1235* * * 6.93 E7 J = 8.56 E10 J = 8.56 E7 kJ/year
_______________________________________________________________________________________________
Rachael Mack: Lamps
 Brand  Voltage (V)  Current (A)  Power (W) 
1  Walmart  120  0.5  60 
2 
 120  0.33  40 
3  Your Zone  120  0.33  (40*5 bulbs) 200W 
4 
 120  0.33  40 
5  Jansjo  120  0.09  10.8 
6  Jansjo  100  0.09  0.09 
7  Walmart  120  0.12  14 
8 
 120  0.5  60 
9 
 120  0.33  40 
10  Walmart  120  0.12  14 
Average 


 48.78 
Assuming there is on average one lamp per person, and each person uses it daily for about 1.5 hours. (Approximately 93% of the total student body lives on campus – 1717 students.)
48.78 J/s * 60 s/min * 90 min/day * 365 day/yr = 9.61 E7 J/yr
9.61 E7 J/yr * 1717 students = 1.65 E8 kJ/yr
_______________________________________________________________________________________________
*Reuben Biel, Television*
Room No  Brand  Volt (V)  Current (A)  Wattage (W)  Time (hrs_used/day)  Occupants  Gender  kJ Used per Room per Day  kJ Used per Individual per Day 
1  Sylvania  120  0.44  53  0.57  3  M  109.0285714  36.34285714 
2  Emerson  120  0.5  60  1  2  F  216  108 
3    0  0  0  0  2  M  0  0 
4  Orion  120  0.92  110  1  2  F  396  198 
5  Olevin  120  1  100  1.5  3  M  540  180 
6    0  0  0  0  2  F  0  0 
7    0  0  0  0  3  M  0  0 
8  Emerson  120  0.46  55  1  2  F  198  99 
9  Magnavox  120  2  240  0.57  1  M  493.7142857  493.7142857 
10  Magnavox  120  0.33  40  5  1  M  720  720 
11  RCA  120  0.46  55  1.5  1  F  297  297 
12  LG  120  1.25  150  6  1  M  3240  3240 
13  Insignia  120  0.58  70  0.5  0.5  F  126   
13A  LG  120  1.25  150  2  0.5  F  1080   
13 Total 
 0  0  0  0  1  F  0  1206 
14    0  0  0  0  1  F  0  0 
Assuming that Televisions only draw energy while being used (false assumption so is an underestimate of actual usage):
Average Usage per Female per Day (including those without TVs): 273 kJ/day
Average Usage per Male per Day (including those without TVs): 667 kJ/day
If there are approx. 960 females (54.8%) and 790 males on campus (Total 1750 students), then:
Total Female Usage per Year = 273 kJ/femaleday*365 days/yr*960 females = 9.55E7kJ/yr
Total Male Usage per Year = 667 kJ/maleday*365 days/yr*790 males = 1.92E8kJ/yr
Total Energy Usage per Year = 9.55E7kJ/yr + 1.92E8kJ/yr = 2.88E8kJ/yr
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Kimberly Bittler, Electric alarm/radio clocks
 Room  Brand  Voltage (V)  Current (A)  Power (W) 
1  0  0  0  0  
2  0  0  0  0  
3  0  0  0  0  
4  Timex  120  0.05  6  
5  Memorex  15  1  15  
6  Sony  120  0.04  5  
6  0  0  0  0  
6  0  0  0  0  
7  Sony  120  0.04  5  
8  RCA  22  1  22  
8  iPod  15  1.5  22.5  
9  0  0  0  0  
9  0  0  0  0  
9  0  0  0  0  
10  0  0  0  0  
11  0  0  0  0  
12  Sony  120  0.04  5  
13  0  0  0  0  
14  Sony  120  0.04  5  
15  Memorex  120  0.04  5  
16  0  0  0  0 

Number of students with alarm clocks:
9/21 students in the survey = 43 % x ~1750 students on campus = 752 students
Average power use of alarm clocks: 10.0 W
Total Average power use (including nonowners): 4.3 W
Yearly Average Power Use per student:
4.3 J/sec x 60 sec/min x 60 min/hr x 24 hr/day x 365 day/yr = 1.36 x 10^8 J/yr
Campus Power use:
1.36 x 10^8 J/yr x 1750 students = 2.40 x 10^11 J/yr x 1 kJ/1000 J = 2.40 x 10^8 kJ/yr
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Josie Thiele, Microwave Oven
 Brand  Voltage (V)  Current (A)  Power (W) 
1  Cuisinart  120  8  1000 
2 
 120  8  1000 
3  GE  120  9  1100 
4 
 120  9  1100 
5  LG  120  13  1500 
6 
 120  13  1500 
7 
 120  13  1500 
8  Sharp  120  9  1100 
9 
 120  9  1100 
10  Frigidaire  150  6  900 
Average 


 1180 
Assuming that there is one microwave per room (and each room has 2 people in it), and each room uses it for 20 minutes a day.
Yearly Average Power Use per microwave
1180J/s*60s/min*20min/day*365day/yr*1kJ/1000J=5.2*10^5kJ/yr
Annual Campus Power Use
Assuming there is one per room, ~875 rooms
5.2*10^5kJ*875rooms=4.6*10^8kJ/yr
*Erin SchnettlerHair Straightners
Sample  Brand  Voltage (V)  Power (W) 
1  Emperor  110V  200W 
2  Solia  110V  58W 
3  Sedu  110V  72W 
4  Solia  110V  58W 
5  CHI  110V  35W 
6  Sedu  110V  72W 
7  Conair  120V  36W 
8  Solia  110V  58W 
9  Hot Tools  110V  170W 
10  Solano  110V  135W 
Avg.  89.4W 

Average Energy Consumption per year assuming 10 minutes of daily use
89.4J/sec*(60sec/min)(10min/day)(365days/year)=19578600 J/year
Avg. Energy Consumption per year assuming that use is limited to all females on campus:
19578600 J * 1,764 students * .548 =3.454*10^10 J (1 kJ/1000 J) = 3.45*10^7 kJ/year
_______________________________________________________________________________________________
Greg Klein: Coffee Makers
 Brand  Voltage (V)  Current (A)  Power (W) 
1  Mr. Coffee  120  7.5  900 
2 
 120  7.5  900 
3  Black and Decker  120  10  1200 
4  Cuisinart  120  13.833  1660 
5 
 120  13.833  1660 
6  Cuisinart  120  9.166  1100 
7 
 120  9.166  1100 
8  Hamilton Beach  120  7.5  900 
9  Hamilton Beach  120  12  1140 
10 
 120  12  1140 
Average  1812.5 

Assuming about one in ten students has a coffee maker:
0.1 x 1764 students = 176.4 students
Average yearly power consumption, assuming 5 minutes daily use:
1170 J / sec x 60 sec / min * 5 min x 365 = 1.281 x 10^8 J / year
Total power consumption for the campus:
1.281 x 10^8 (J / year x students) x 176.4 students = 2.260 x 10^10 J / year
2.260 x 10^7 kJ / year
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Andy Oakes, Laptop Chargers
> Sample  Brand  Voltage  Current  Power 
1  Macbook  16.5V  3.65A  60W 
2  Macbook Pro  16.5V  3.65A  60W 
3  Dell Latitude  19.5V  3.34A  65W 
4  Dell Inspiron  19.5V  3.34A  65W 
5  Macbook Pro  16.5V  4.6A  85W 
6  HP Compaq  19V  4.74A  90W 
7  Macbook Pro  16.5V  3.65A  60W 
8  Macbook  16.5V  3.65A  60W 
9  Dell Inspiron  19.5V  3.34A  65W 
10  Gateway NV  19V  4.74A  90W 
Average 


 70W 
Average Energy Consuption a year assuming 300 minutes daily use.
70 J/sec * 60 sec/min * 300 min/day * 365 day/year = 4.60E8 J/year
Assuming everyone on campus has a laptop
4.60E8 J * 1867 = 8.59E11 J = 8.59E8 kJ
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Sarah Dallas Cell Phone Chargers
sample  brand  voltage (V)  current (A)  Power (W) 

1  LG  5  1  5 
2  BlackBerry  5  0.7  3.5 
3  BlackBerry  5  0.7  3.5 
4  Samsung  5  0.7  3.5 
5  LG  5.1  0.7  3.57 
6  LG  5.1  0.7  3.57 
7  Motorola  5  0.55  2.75 
8  LG  4.8  0.9  4.32 
9  LG  5.1  0.7  3.57 
10  BlackBerry  5  0.7  3.5 
Average 


 3.678 
1764 chargers on campus, because every student has a cell phone
Assume they are used by everyone for 3 hours a day every day of the year
3.678 J/sec * 60 sec/min * 60 min/hr * 3 hr/day * 365 days/yr = 1.45E7 J/yr
Power*#of chargers >> 1.45E7 * 1764 = 2.56E10 J >> 2.56E7 kJ
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Trevor Poole  Game Consoles
Sample #  Brand  Use (min/week)  Voltage (V)  Current (A)  Power (W) 

1  Xbox 360  120  12  12.1  150 
2  None  0  0  0  0 
3  None  0  0  0  0 
4  Xbox 360  60  12  14.2  175 
5  None 




6  Wii  90  12  3.7  33 
7  None  0  0  0  0 
8  Xbox 360  90  12  14.2  175 
9  Wii  90  12  3.70  33 
10  None 




40% of rooms total have game consoles, however all surveyed were male. 1764 total students * (.4 (males on campus) * .5 (males with game consoles)) =.2 total, or 353 game consoles on campus
Used for an average of 90 minutes per day
113.2J/s * 60seconds/minute * 60 mins/hour * 1.5 hours/ day * 365 days/year = 223,117.2 kJ per year per console.
223,117.2 kJ * 353 consoles = 78,760,371.6 kJ
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Amy Holmen, mini fridges
Sample  Brand  Votage (V)  Current (A)  Power (W) 

1  GE  120  0.75  90 
2  MagicChef  115  1.2  138 
3  MagicChef  115  1.3  149 
4  Sanyo  120  1.0  120 
5  Haier  110  1.1  121 
6  Danby  120  0.85  102 
7  none       
8  GE  120  0.75  90 
9  none       
10  MagicChef  115  1.2  138 


 AVERAGE  118.5 
Yearly Average power use per fridge
Let us assume that the fridge is plugged in and running all day for 9 months of the year (our school year)
118.5 J/sec * 60 sec/1 min * 60 min/1hr * 24 hr/day * 270 day/year= 2.7 *10^6 kJ per year per fridge
Annual Campus Power Use
Assume that 80% of rooms have a fridge, so 750 rooms * 0.80= 600 fridges on campus
2.7*10^6 kJ/year/fridge * 600 fridges= 1.62*10^9 kJ/year
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Homework 3 The basics of biomass (due 2/26/2010)
Some Links to get things started
http://blogs.middlebury.edu/biomass/
http://www.colgate.edu/DesktopDefault1.aspx?tabid=4354
http://www.fs.fed.us/woodybiomass/state.shtml
http://www.aashe.org/wiki/climateplanningguide/carbonoffsets.php
http://alethonews.wordpress.com/2010/01/12/upinsmoke/
Questions to consider:
1) It is generally assumed that Maine is harvesting wood at a rate equal to the annual growth rate. Is this true? What are Maine’s requirements for sustainable growth?
2) If question one is true, how does a biomass plant meet the additionally principle for carbon neutrality? Do we have additional biomass capacity in Maine?
3) Using Middlebury’s wood consumption as a guide, how many acres of forest are required to meet the fuel requirements of the proposed biomass plant at Colby? How many acres of forest will need to be harvested to meet Colby’s fuels supply in a sustainable fashion?
A) Divide the class into groups of four and decide which group will address which question.
B) Starting with the resources provided at the beginning of this question, generate an annotated bibliography of sources to help answer your question.
C) Generate two figures diagramming the material flows used to help answer your question.
D) For class on Friday, 2/26. Be prepared to present your two figures and your strategy for answering your group question.
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Works Cited
Gibbs, Jeff. "Green Nightmare: Burning Biomass is Not Renewable Energy." The Huffington Post. 17 Dec. 2009. Web. 23 Feb. 2010. <http://www.huffingtonpost.com/jeffgibbs/greennightmareburningb_b_395553.html>.
The Gibb’s article gives an opposing view, explaining why biomass generated energy is not a renewable energy source.
MaineForest Service. MaineForest Service Assessment of Sustainable Biomass Availability. Rep. Maine State Government, 17 July 2008. Web. 24 Feb. 2010. <http://www.maine.gov/doc/mfs/pubs/pdf/biomass_memo_071708.pdf>.
The Maine Forest Service Report provided information regarding the current biomass of Maine's forests, and the sustainable yield for the forests.
MiddleburyCollege. "Biomass at Middlebury." The Middlebury Blog Network. Web. 24 Feb. 2010. <http://blogs.middlebury.edu/biomass/about/>.
The Middlebury site was used to obtain general as well as specific information regarding the use of biomass technology at MiddleburyCollege. This information was used to determine what would be necessary for Colby to use biomass technology.
National Alliance of Forest Owners. "Carbon Neutrality of Energy from Forest Biomass." Carbon Neutrality of Energy from Forest Biomass. NAFO (National Alliance of Forest Owners), 2009. Web. 23 Feb. 2010. <http://nafoalliance.org/carbonneutralityofenergyfromforestbiomass/>.
The National Alliance of Forest Owners site provides background information in regards to the carbon neutrality of producing energy from forest biomass.
Sarah, Kim, Reuben, and Trevor
Homework 4  Due 3/5/2010
Book Problems  Chapter 9: 4, 6, 9, 12, 13
Additional Problems
1. Freon, CFC12, is building up in the atmosphere at a rate of 1.4 %/year. If the current concentration of CFC12 is 519 pptv (parts per trillion by volume), what is the net molar flux of CFC12 to the atmosphere in one year?
2. Calculate the maximum wavelength of radiation that could have sufficient energy to effect the dissociation of nitric oxide (NO). In what regions of the atmosphere would such radiation be available? (The bond energy of NO is 90.2 kJ/mol)
3. The Chapman mechanism of stratospheric ozone production was successful at predicting the shape of the stratospheric ozone concentration profile, but overestimated the ozone concentration. We now understand that simple ozone models involving only O_{2}, O and O_{3}species are incomplete. What are the major processes controlling the stratospheric ozone concentration profile (shape and concentration) and how have atmospheric emissions in the last 50 years modified the profile. (HW Key )
Homework 5  Due 4/7/2010
Book Problems 11: 2, 7, 9, 14, 13: 4, 7, 11,17
Additional Problem: During a recent talk at the Maine Water Quality Conference, Professor Steve Kahl from UMO showed convincing evidence of decreased acid deposition to Maine based on decreasing sulfate concentrations in Maine lakes. During the same 10 year period the nitrate concentrations have also decreased, but much more slowly. Explain these findings in terms of the chemistry of “acid rain” including current regulations, atmospheric chemistry, and emission sources.
Homework 6  Due 4/16/2010
Lake Problem Set I.
Consider a lake of infinite horizontal dimension, a depth of 20 meters, and a thermoclineat 10 meters. The epilimnetic temperature is 25 ^{o}C. The hypolimnetic temperature is 6^{o}C. Both layers are well mixed vertically. The alkalinity of the lake is 0.10 mM.
1) Calculate the equilibrium concentration of oxygen at depths of 5 and 15 meters in units of ppm and moles/liter.
2) If the average wind speed on the lake is 10 meters/second, what rate of net biological oxygen demand (moles/liter sec) is required to decrease the oxygen concentration to 90% of saturation at 5 meters?
3) Based on the biological oxygen demand, how long will it take the hypolimnion to go anoxic (<1 ppm O2)?
Key: Lake problem 2010 O2 solubility.xls
Homework 7  Due 4/23/2010
Lake Problem Set II.
Consider a lake of infinite horizontal dimension, a depth of 20 meters, and a thermocline at 10 meters. The epilimnetic temperature is 25 ^{o}C. The hypolimnetic temperature is 6^{o} C. Both layers are well mixed vertically. The alkalinity of the lake is 0.10 mM.
1) Calculate the pH of the epilimnion assuming it is in equilibrium with CO_{2} in the atmosphere.
2) Assuming that the phosphate concentration of the lake was 20 ppb (as P) at the time of the spring turnover, calculate the oxygen concentration in the lake at 5 meters and 15 meters after all the P in the epilimnion is consumed by photosynthesis, settles, and is respired in the hypolimnion.
3) What is the pH of the hypolimnion after the event described in step 2 occurs?
4) By how much will the nitrate in the hypolimnion increase after the event described in step 2 occurs?