# Group Activity � CARTESIAN DIVER - DOC by yJ3P74

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```									                        CLINM WORKSHOP
CLASSROOM ENERGY AUDIT

NAME(S): Lisa Bozzo, Maryam Raymond, Don Angelo

SCIENCE CONCEPT (Main Idea): Students conduct an energy audit
to determine how much carbon dioxide their classroom is releasing
into the atmosphere and then make recommendations for
minimizing the classroom’s carbon footprint.

CONCEPTUAL BACKGROUND: Before talking about energy
efficiency, it is helpful to have an understanding of units of power
and energy (like watts, kilowatts, and kilowatt-hours). Power tells
us the quantity of energy that changed during a certain period of
time. For example, one watt is equal to one joule per second. A 60-
watt light bulb converts 60-joules of electrical energy into thermal
energy (heat) and radiant energy (heat) each second.

RELATIONSHIP TO CALIFORNIA SCIENCE (and other subjects)
CONTENT STANDARDS: Science: 6.3 Heat (Thermal Energy), 6.6
Resources, 6.7 Investigation and Experimentation. Math:

LEARNING OBJECTIVES: Students will be able to:
1. understand the units of power and energy.
2. determine the cost of running various classroom and household
appliances.
3. find the amount of carbon dioxide emitted for different types of
energy consumption.
4. determine ways of reducing energy consumption and carbon
dioxide output.

EVALUATION IDEAS:
1. formative: class discussions

2. summative: strategies to reduce classroom energy use, end-of-
unit test, home energy audit
LESSON IMPLEMENTATION DETAILS:

1. Make a list on the board of devices and activities that require
power. Challenge your students to try to rank these activities
from least to highest power consumption. Next ask the students
to estimate how much power (in watts) each activity consumes.
After they have made their estimates, write the actual amounts
on the board.

Estimated Power Draw          Activity: Actual Power Draw (watts)
____________________          Freight Train: 3,730,000
____________________          Hand-Held Flashlight: 1
____________________          Incandescent Lamp Bulb: 60-100
____________________          Human Sitting Calmly: 75
____________________          Human Walking: 383
____________________          Human Running: 745
____________________          CFL Light Bulb: 13-25
____________________          Average Car: 89,520
____________________          Space Shuttle Takeoff: 11,000,000,000

The list shows typical power consumption for various activities,
but to know how much energy is consumed we have to add in
the time factor. For example: A light bulb drawing 100 watts of
power left on for 10 hours consumes 1,000 watt-hours (or 1
kilowatt-hour) of energy. In other words, WATT (power) tells us
how hungry a device is for power. WATT-HOUR (energy) is the
quantity of electrical energy the device used over a period of
time.

2. Ask students if they know where the energy they use on a daily
basis comes from. (When students say "the gas station" or "the
electric company," ask them to go further. Where does the gas
that is delivered to the gas station come from? Where is the
power plant that produces the electricity? What type of fossil
fuel or nuclear source is transformed into the electric energy?)
Explain to students that energy is power usage over time.
Power is measured in watts. Electrical energy usage is usually
measured in kilowatt-hours (kWh—a kilowatt-hour is when 1000
watts is used for 1 hour).
3. Bring in several electricity bills or find a sample to use (NSTAR
provides a sample online). Review the bill with students. What
is charged for in the bill? (There is usually a charge for energy
consumption and one for energy delivery.) Does the charge for
a kilowatt-hour remain the same throughout the year? (Charges
for kilowatt-hours usually vary throughout the year depending
on how much energy a household uses or whether the energy
is being delivered during a time of year when energy is in high
demand. In addition, costs usually vary by region.) In which
months does the family use the most electricity? (Many families
use more electricity during the summer months.) What might be
the reason for this? (Increased air conditioning use is one
reason.)
4. Tell students they will now calculate how much it costs to run a
TV all night for a month. To estimate the appliance's energy
use, have students use the following formula (students should
find out how much a kilowatt-hour costs in their community):

Power (Watts) × Time (Hours) = 1 Kilowatt-Hour / 1000
Watts
= Daily Kilowatt-Hour (kWh) Consumption
Daily kWh Consumption × Cost per kWh = Energy Use
Cost

If a 200-Watt TV were left on 12 hours and each kWh
costs 10 cents, the cost to run the run the TV for all night
for one month would be \$7.20 (200 Watts × 12 Hours ×
0.001 = 2.4 Kilowatt-Hours; 2.4 Kilowatt-Hours × \$0.10
per Kilowatt-Hour = \$0.24; \$0.24 × 30 days = \$7.20).

Now that students are familiar with the concept of watts you can
do an energy audit. Ask students to estimate how many watts
the classroom uses on average. Look around the classroom
and think about all the power being used.

2. Use watt meters or the power consumption chart to tally up the
total power being used in your classroom.

3. Discuss the results with students. Which appliances use the
most power? Which use the least? What steps could students
and teachers take to reduce the power used in a classroom?
How many watt-hours of energy are used to power this
classroom for 1 hour? How many watt-hours of energy are used
to power this classroom for a full school day (8 hours)? How
many kilowatt-hours is this (divide previous answer by 1,000.)?
If electricity costs 12 cents per kilowatt-hour, how much money
does it cost to power this classroom for a full school day?

CONNECTIONS TO OTHER SUBJECTS (e.g. math, literacy, etc.):
Math, technology

DIFFERENTIATION PLANS:
1. Have students do an energy audit at home to determine how
much carbon dioxide their family is releasing into the
atmosphere and design a plan for reducing their family’s
carbon footprint. Allow students to use the watt meters.
2. Have the students do a case study of their school’s energy
use and suggest changes for improvement.

LIST OF MATERIALS (PER CLASS, GROUP, OR STUDENT): video
clip: Green Ninja “Footprint Renovations”; chart showing average
power consumption of electrical appliances (one per group); Kill A Watt
electricity usage monitor (one per group- optional); calculator (optional)

If you do not have access to a watt meter, you can find charts showing average
power consumption from various electrical appliances at:

http://www.energysavers.gov/your_home/appliances/index.cfm/mytopic=10040

http://www.absak.com/library/power-consumption-table

NOTES, SPECIAL INSTRUCTIONS, SAFETY CONCERNS, ETC.