Student Worksheet

Instructions

In this activity you will be working out how much energy you use on average over one day! Follow the instructions to fill in table 1.

Step 1:

Write down the name of the appliance in column A. Write down the Watts for that appliance in column B. You also have a general guide to the wattage of many appliances. Only use the wattage printed on the appliance if you can easily see without poking around.

Estimate how many hours you used the appliance for and write it down in column C

Step 2:

In column D work out the units of electricity used. To do this:

Multiply Watts by hours used (column B x column C)
Divide by 1000
Write the answer into column E

Step 3:

In column F write the cost by multiplying the units used by the price per unit.

You can find the unit price on the electricity bill. It is usually represented as
rate c/kWh (cents per kilowatts)

If you prefer do your calculations on a spreadsheet application.

Table 1.

Questions

When your table is filled out, answer the following questions

How much total energy did you use in one day?

How do you think the information that you have found out about your energy use will change your energy consumption behaviour in the future?

Are there any ways that you could use less?

Typical Power Ratings

If it is difficult to find the power rating written on the appliance, use this table as a guide. However be aware that this rating is only a guide and power ratings may vary greatly from one appliance to another.

Appliance	Typical Power Rating
Ceiling fan	65-75W
Computer (PC and monitor)	190 W
Cordless phone (average standby)	30 W
Dishwasher (2 star rating, 1hr/cycle, 12 Places) 1 star	1335 W
Dishwasher (2 star rating, 1hr/cycle, 12 Places) 2 star	950 W
Dishwasher (2 star rating, 1hr/cycle, 12 Places) 3 star	712 W
Electric air conditioning (evaporative)	400 W
Electric air conditioning (split cycle, 2 star rating)	1400 W
Electric air conditioning (wall unit, 2 star rating)	1410 W
Electric central heating	4000 W
Electric oven (fan assisted)	1500 W
Electric stove top cooking (large hotplate)	1100 W
Electric stove top cooking (small hotplate)	700 W
Electric strip heater (no thermostat)	1000 W
Energy efficient light globe	15 W
Fax machine	20 W
Fish tank	50-1210 W
Fluorescent light tube	13/20/40 W
Fridge (1 door) 350-400 L (2 star rating)	1060 W
Fridge (2 door) 350-420 L (3 star rating)	1671 W
Gas central heating	19440 MJ
Gas heater (large wall unit)	35 MJ
Gas heater (small wall unit)	12 MJ
Gas oven	12 MJ
Gas stove top cooking (large stove size)	16 MJ
Gas stove top cooking (small stove size)	10 MJ
Kettle	2400 W
Microwave	1600 W
Photocopier (active)	75 W
Photocopier (standby)	180 W
Printer	10-40 W
Scanner	12 W
Small appliances (radio, portable fan)	12 W
Standard light globe	40/60/100 W
Television (LCD)	270 W
Television (Plasma)	311 W
Toaster	2400 W
DVD / VCR	25 W
Washing dishes - electric hot water system (10L/sink/wash)	330 W
Washing dishes - gas hot water system (10L/sink/wash)	1.89 MJ

How Much Electricity Did You Use Today?

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