Home Energy Consumption

To make decisions about how to conserve energy, we need to understand how we use it. The consumption of electricity by various appliances varies tremendously. Sometimes, we think that conserving energy means doing without modern amenities, but by learning which appliances use the most energy, we can learn ways to cut electricity use (and cost) without giving up convenience. Reducing the energy used by space (air) heating by 2% can save more energy than is typically used by televisions, stereos, and DVD players combined. By realizing that the use of electrical appliances adds up, we learn that every little bit of electricity saved helps the environment.

When utility companies charge us for electricity, they do so according to how many kilowatt (kW) we have used. A watt (W) is a unit used to indicate how much electrical energy has been used. A kilowatt is 1000 watts. An appliance's "wattage" refers to the number of watts an appliance uses in an hour.

If 1000 W (1 kW) of power is used for one hour, that is a kilowatt-hour (kWh). Thus, if an appliance that uses 1000 W of power is used for one hour, 1 kWh of power has been used. Ten 100 W light bulbs left on for an hour would also equal 1 kWh of power, as would one 100 W bulb left on for 10 hours. A heater that uses 1500 W of power per hour consumes 1.5 kWh of power. Since 200 W equals 0.2 kW, a 200 W television left on for 1 hour would use 0.2 kWh.

Generally, converting electrical energy to heat energy takes a lot of electricity to obtain useable amounts of heat. Thus, appliances that are used to generate heat, such as stoves, water heaters, space heaters, etc. use a lot of electricity. Some other appliances such as radios and stereos, use very little. When used often, however, their electricity consumption can add up.

By knowing how much electricity costs per kWh, we can get an idea of how much it would cost to operate an appliance for a period of time. In this activity, you will survey your home to determine the electrical appliances used most often and estimate the number of hours they are used each month. Then, using an average rate (cost) per kWh of electricity, you will calculate how much money is spent on each appliance per month.

To calculate your average rate per kWh you will need one of your family's electrical bills or visit http://www.nbpower.com/en/customers/rates_policies/index.html.

Nobody wants to waste energy and nobody wants to waste money. Why, then, do we use so much energy and waste so much of it? The answer to that question involves personal ethics, priorities, and knowledge. Most people would reduce their energy use if they knew how and it were not too inconvenient to do. Space (air) heating uses about 50% of the energy use in our homes. Water heating uses about 13% while lighting and refrigeration use another 9% each. All other use accounts for the remaining 20%. Clearly, if you wanted to do only one thing to conserve energy, you would reduce your space heating use. It is important to remember, though, that the energy used by "small" energy users like TVs and stereos add up.

Transportation is another major energy user. Personal automobiles are the largest single energy user over which we have personal control. They use about 14% of the total energy used each year in North America. That is more than home space heating, which uses about 11%. If you really want to save both energy and money, you should consider ways to reduce driving.

Procedure:

1. Answer the following questions by making a total guess:

a) How much does it cost to watch TV for an hour?

b) Which costs more, an hour of listening to the stereo or leaving a light on for an hour?

c) In your home, what appliance uses the most electricity?

d) How much is the average monthly electricity bill for your family?

2. Examine various, commonly used electrical appliances to find and record the wattage marked on them. This is usually found on a label or plate attached to the back of the appliance. It often states such information as model number, voltage and wattage. Make sure to include things such as toaster, oven, water heater, and space heaters, as well as other smaller appliances.

3. To calculate the cost of using the appliance each month, us the following equation:

days used/month x hours used/day x kW x rate/kWh = cost/month

note: for some appliances, you may want to calculate the kWh per use or day rather than per hour.

4. Record your data and calculations in a table such as the one below.

Questions

1. What are the two main energy users in your home?

2. If you cut back your use of the single top energy user by 5%, how much money would your family save each month?

3. If your family reduced its total electricity use by 10%, how much money would you save each month?

4. List the three most necessary electricity users in your home. Why is each necessary? What alternatives exist?

5. List the three least necessary electricity users in your home. For each, state what you would do without it.

6. What energy use could you completely eliminate from your home?

7. Compare the major energy users with those that use less electricity in regard to their importance. How much electricity is used to fulfill "wants" as opposed to "needs"?

8. Calculate the energy use per person in your family. How does this compare with people in larger or smaller families than your own

9. State whether you agree or disagree with the following state: "We can reduce electricity use in our homes by 15% and still maintain a comfortable lifestyle." Support your position.

10. How can saving energy in the home help the environment?

11. Is it in the best interest for power commissions to promote conservation of electricity? Why or why not?

12. Contact the NB Power Commission and request information concerning conservation.

13. What are some ways in which energy could be conserved in the home?

14. What are some ways to conserve energy in transportation?

15. If most of our energy is used to fulfill needs, does that mean we can't reduce the energy used to fill needs? Explain.

16. Why should you conserve if other people won't?