Below are the Excel spreadsheets you will need to work on your project.  Have fun!

The electricity we use in our homes is produced at power plants. What supplies the power plants creating this electricity is a "primary source" of energy, the mix of which varies from state to state.  California uses a mix of primary sources that includes natural gas, nuclear, large-scale hydro, coal, and renewables, such as wind and solar, to supply electricity to homes and businesses in the state.

In 2006, 78.1% of the electricity was supplied by primary sources obtained in-state, while 21.9% was imported from outside the state of California, from the Pacific Northwest and the Southwest.  Natural gas is the largest primary source used to produce electricity in California (41.5%). Coal is used to supply 15% of the electricity and 10.9% is from renewables (such as solar and wind). See: http://energyalmanac.ca.gov/overview/energy_sources.html.

The mix of primary energy you use to create electricity will change your carbon footprint! Why?

End-User Fuel Carbon Calculator (Excel 2003 version) - This table will help you calculate the contribution to CO₂ for each of the various energy sources that we use to provide services such as heating our homes, driving our cars, cooling our office buildings, and running equipment in industry. Why do the various end-user fuels differ in terms of carbon even if they supply the same service?

What are the least carbon intensive end-user fuels? Are these the best solutions for reducing our global carbon footprint? If yes, why? If no, why not? A number of these fuels don't result in a carbon contribution...or do they?

Other states and countries use different sources of primary energy then California does and, thus, have different "carbon intensities" (note the U.S. average as compared to California!). For a more complete table, please click here (Pdf version).  Which country has the lowest carbon intensity?  Why do you think that is the case?  What primary sources of energy do you think they use?  Which has the highest?  What sources of primary energy do you think they use?

SAMPLES:

Digital Power Meter Worksheet  (Excel 2003 version) - We can measure how many watts (a unit of electricity) used by various household appliances and consumer electronics (e.g.,  refrigerator, microwave, toaster oven, coffee maker, computer, TIVO, X-Box, hair dryer, curler, straightener, electric toothbrush, etc.) with a digital power meter (pictured to right).

The amount of watts each of these appliances uses varies over time. Why?

For example, what would make a refrigerator show varying watt measures? How about a microwave? What other appliances vary in wattage depending upon use?

Do all of your appliances read zero (0) on your meter when they are "off"? Which ones don't and why not?

What appliance in your home measures the highest in wattage? What measures the lowest? Of the lowest and highest measures you obtained which appliance is the largest energy consumer? Why?

Remember, each watt used is carbon emitted and the type of primary fuel used to create that watt of electricity will result in a varying amount of carbon produced!

Taking it Home

Confront Carbon at Home Worksheet (Excel 2003 version) - This worksheet allows you to track your utility bills for one year, two years, or just compare months.  You can analyze your energy use and get your utility bills online at Pacific Gas and Electric (PG&E) which supplies Davis with gas and electricity.  It might be interesting to use this spreadsheet by entering data for a summer month (like August) and a winter month (like December) to see what differences there might be between those two months. You can also enter an entire two years worth of data to see the differences between them. What might make the difference between two years? Months? What kinds of things could you do to your home to reduce electricity and/or gas consumption?

This worksheet can also be used for establishing a baseline. After you implement various energy efficient measures in your home, you can then add a second year of data. What kind of difference might you see in your utility bill if you implement energy efficiency measures in your home? How might that change your "carbon footprint"? Do you think there will be a measurable change? Why? Why not?

Sample Utility Bill - Your home bill will show two types of "fuel" used: therms of gas and electricity. This sample utility bill highlights the pieces of data you will need from your utility bill to complete the Confront Carbon at Home Worksheet.

Other Carbon Footprint Calculators:

http://www.ecologyfund.com/ecology/res_bestfoot.html

http://zerofootprint.net/youth/neew

http://www.nature.org/initiatives/climatechange/calculator/

http://169.237.35.250/~dylan/bike_challenge/

Ideas of What You can do to Reduce Your Carbon Footprint:

Environmental Defense Fund: http://www.fightglobalwarming.com/page.cfm?tagID=135

U.S. Environmental Protection Agency: http://www.epa.gov/climatechange/kids/difference.html