Section 4. Energy in Your Life (25 pts)

In this homework assignment you are going to estimate your daily and yearly electrical use.

1. Make a list of all the electrical appliances you use in an ordinary day, including light bulbs,

HVAC, blow dryers, TVs, microwave oven, refrigerator, computer, stove, washer, dryer, etc. If

you live in a coop etc, list just the appliances that you use yourself (and be aware that you'll be

underestimating your energy use in this assignment). Alternatively, you could also calculate

your "share" of energy use in communal spaces.

2. Find the wattage or amperage ratings of these appliances by checking the labels. Write

these numbers next to the appliance on the list. My radio uses 6 watts, but an iron might use

1200 watts.

3. Keep track of how many minutes or hours you use these appliances in one day. Convert to

hours (10 minutes = 10/60 hr = 0.17 hr). Refrigerators get 24 hrs of use/day. List the hours of

use/day on your list, beside the appliance and its power use./n4. If your appliance has a wattage rating, multiply the number of watts by the number of hours

used per day. This is the number of Wh of energy that appliance used in a day.

If your appliance only gives an amperage rating, multiply the amps times 120 V (the voltage of

the electrical line) to get an approximate wattage. [Note: Power (watts) is the work done per

unit time = | (current measured in amps) x V (voltage measured in volts).] Then follow the

instructions above to estimate kWh. Write the kWh used per day on the line with the appliance.

Also note appliances that use standby energy.

5. Add up the total kWh used by all your appliances in a day to get the total daily energy use.