Student Handout #1
Energy Use at Your House

How Much Energy Used in an Hour?

GHG’s per kilowatt-hour (kWh)

• If your community uses hydro-generated electricity, 1 kWh results in 0 grams of GHG emissions approximately. (The actual figure for your community may be higher if flooding for a hydro dam increased GHG emissions (from decaying trees in the flood area), if emissions from dam construction were factored in, or if some diesel is used for electricity generation during peak load times.)
• If your community uses diesel-generated electricity, 1 kWh = 795 grams of GHG emissions. Note: To get the full GHG emissions for your community, add on the diesel fuel used to truck it in. A diesel truck that has a carrying capacity of 45,000 litres uses approximately 0.625 litres of diesel fuel per km. Each litre used emits 2830 grams of GHGs. (That equals 1769 grams of GHGs per kilometer.) If your truck is carrying 45,000 litres of diesel and drives 1000 km into your community, you will need to add 1769/45,000 x 1000=39.3 grams/litre to your rate. One other useful conversion factor: One litre of diesel will produce about 3.56 kWh of electricity.
  
  Find out how many km your diesel travels into your community, and calculate how many grams of GHG emissions this will add to the basic rate of 795 grams of GHG per kWh.
• If your home uses wind- or solar-generated electricity, 1 kWh results in 0 grams of GHG emissions.

How Many Watts? How Many GHGs?

Look on your electricity bill to see how many kilowatt-hours (kWh) your family has used during the billing period. Fill in the chart to get an idea of how your family consumes all that electricity.

Get your family to help you complete the chart, following this order:

1. Write down your major appliances and energy-using devices. (For this chart, omit your hot water heater and furnace.)
2. Estimate with your family how many hours per week (on average) this appliance is used.
3. Using the table above, write in the number of watts used per hour of operation.
4. Multiply “b” times “c” to find the total watts per week.
5. Divide by 1,000 to get the kilowatt hours (kWh) per week
6. Check your electricity bill to find the cost for each kWh in your community.
7. Multiply “e” times “f” to get the cost per week to operate this appliance.
8. Using the “GHGs per Kilowatt-hour” table above, write in the number of grams of GHG per kWh for your type of energy generation.
9. Multiply “e” times “h” to get the total GHG emissions created by this appliance/device in a week.
10. At the bottom, total all the columns.
11. To figure out how many kilowatt-hours your family uses for heating your hot water and your home, look below.

More Pieces of the Energy Puzzle: Hot Water & Heating

Two major GHG-emitters missing from this chart are:

Hot water – How do you heat the water in your hot water tank? Hot water is a huge energy-guzzler!

Heating – How do you heat your home? Home heating, especially when it uses fossil fuels, is a big cause of GHG emissions.

• Oil Heat: If your family heats your house by using oil, check out your family’s heating fuel bill to see how many GHGs your home has emitted during the billing period. The bill will show how many litres of oil have been used during that time. Burning a litre of oil creates 2830 grams of GHGs. Multiply the number of litres on your bill by 2830 grams to see how many grams of GHGs you have emitted. You can also figure out the kWh used in heating your hot water by electricity. Just use the method below (Electrical Heat – home & hot water). When you subtract all the kilowatt-hours used by appliances, what you have left over will be (roughly) the amount used to heat your hot water. As a check, the amount of energy to heat your hot water should be approximately 10 per cent of the amount of energy used to heat your house. (Remember that a litre of heating oil contains about 8 kWh of heat, if the furnace is about 75% efficient.)
• Wood Heat: Although wood burning creates some human health problems, it is low in the amount of GHGs produced because it is a renewable fuel, so your home will score a 0 in home-heating GHG emissions. You can figure out the kWh used in heating your hot water by electricity. Just use the method below (Electrical Heat – home & hot water). When you subtract all the kWh used by appliances, what you have left over will be (roughly) the amount used to heat your hot water.
• Electrical Heat – home & hot water: If your family heats by electricity, get a rough idea of the kilowatt-hours used for heating and hot water. Figure out how many kilowatt-hours were used by your appliances for the total billing period, and subtract these from the total kilowatt-hours on your bill. The remaining kilowatt hours are probably the ones you used in heating your water and heating your home. (Remember to calculate your GHG emissions by multiplying the kilowatt hours used by the GHG rate for your energy-source.)
• Electrical Heat (meter-reading method): If you heat by electricity, you can estimate how much energy your household uses during one hour of heating by asking your family to turn off everything except the heat for an hour, and reading your meter at the beginning and end of the hour on an average cold day. (Depending on your meter, this may not be easy.) Then multiply by 168 (the number of hours in a week) to see how many kWh you use in a week.

Student Handout #2 (Enrichment)
Some Ways to Reduce Your Energy Use

(This is a guide – prices and savings vary widely and should be checked locally)