Name: ______

Date: ______

Environmental Science

Kill-a-Watt Lab

Introduction

As you know, carbon dioxide (CO2) emissions are a main cause of global warming. Electricity produced by coal-fired power plants puts carbon dioxide into the atmosphere, and according to the EPA, a single kilowatt-hour (kWh) of electricity will generate 1.80 lbs of CO2 emissions in northeast Ohio. This means that a single 100 watt light bulb, if left on for a year, will result in 1,577 pounds of CO2 emissions from a northeast Ohio coal-fired power plant. By identifying wasteful appliances and decreasing our electricity usage, we can decrease our CO2 emissions and help stop global warming.

Purpose

To determine the average daily and yearly carbon emissions from an electrical appliance.

Prediction

Which appliance do you think will produce the most carbon emissions? Why?

Equipment

Calculator

Electrical appliances

Kill-a-Watt electricity usage monitor

Procedure

1.  Choose an appliance from either side of the room; take it to your station without dropping, breaking, or damaging the appliance.

2.  Plug the Kill-a-Watt meter into the electrical outlet at your lab station; then carefully plug the appliance into the Kill-a-Watt device.

3.  With the device measuring watts, copy the number onto the data chart below.

4.  Using this procedure, determine the power usage in watts for ten different appliances.

5.  Complete the chart for each appliance:

·  To calculate kilowatts, divide the watts you measured by 1000.

·  Then, to calculate the daily carbon emissions, multiply the kilowatts by 1.8, and then multiply again by the average number of hours that appliance is used in one day.

·  Finally, to calculate the yearly carbon emissions, multiply the result for daily carbon emissions by 365.

6. Repeat steps 3-5 for the appliance while it is turned off (if possible).

7. Repeat steps 2-6 for a total of eight appliances.

Clean-up

When finished with the data collection, place all appliances back on the side tables in an organized manner, unplug the Kill-a-Watt meter and return it to the front desk.


Data Table

Appliance / On/Off / Watts (W) / Kilowatts (kW) / Hours used per day / Daily CO2 Emissions (lbs) / Yearly CO2 Emissions (lbs)
W ÷ 1000 / kW x hrs x 1.8 / Daily x 365
1. / On
Off
2. / On
Off
3. / On
Off
4. / On
Off
5. / On
Off
6. / On
Off
7. / On
Off
8. / On
Off

Questions & Conclusions

1.  Was your prediction correct? Why do you think this was the case?

2.  If each American switched one incandescent light bulb to a compact fluorescent lightbulb (CFL), it would have the same effect as taking eight million cars off the road, in terms of carbon emissions. What does this tell you about the relationship between electricity usage and carbon emissions?

3.  Which appliance had the most surprising amount of carbon emissions? Explain.

4.  Choose an appliance from your home that you would like to test for power usage and carbon emissions. Name the appliance and describe why you chose it.

5.  Some politicians have proposed putting a tax on carbon emissions. In other words, the more carbon you emit, the more you will have to pay. How do you feel about this? Do you think this will have an effect people’s energy use? Why or why not?