Every student will help prepare a Colby student energy audit of electrical appliances used by the student body. Start by claiming an appliance by adding your name to the table below. You may fill in the rest of your row at a later date.
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 
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 



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.
Post answers to assignment 1 below: (list name, appliance, and then details)
Steve Jobs, Apple laptop computer
Details on the calculations for computer energy consumption ....
_______________________________________________________________________________________________
Example, Blow Drier

Brand 
Voltage (V) 
Current (A) 
Power (W) 
1 
Jilbere 
125 
10 
1250 
2 
Physique 
125 
15 
1875 
3 
Revlon 
125 
15 
1875 
4 
Conair 
125 
15 
1875 
5 
Perfection Classic 
125 
15 
1875 
6 
Vidal Sassoon 
125 
15 
1875 
7 
Conair 
125 
15 
1875 
8 
Conair 
125 
15 
1875 
9 
Conair 
125 
15 
1875 
10 
Conair 
125 
15 
1875 
Average 



1812.5 
Average Energy Consuption a year assuming 10 minutes daily use.
1812.5 J/sec * 60 sec/min * 10 min/day * 365 day/year = 3.97E8 J
Assuming every female (54.8%) on campus and no males use a blow dryer (some guys have hair driers)
3.97E8 J * 1867 * 54.8% = 4.06E11 J = 4.06E8 kJ
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 




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
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
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
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
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
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
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
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.
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
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 )
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.
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
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?