Three numbers explain everything on your electric bill.
What a watt actually is
Electricity arrives at your home as a flow of energy, and like water flowing through a pipe, it has a rate. A watt measures that rate: how much energy a device draws at any given moment. A 60-watt light bulb draws 60 watts while it is on. A 1,500-watt space heater draws 1,500 watts. The number is on the label because it tells you how fast the device consumes energy, which is the thing you pay for.
A kilowatt is simply 1,000 watts. It exists because household-scale loads are easier to talk about in thousands. A 1,500-watt heater is 1.5 kilowatts. A central air conditioner might draw 3.5 kilowatts. The numbers stay manageable.
The unit you pay for
Your electric company does not charge you for watts. It charges you for kilowatt-hours: how many kilowatts you used, multiplied by how many hours you used them. A 1.5-kilowatt heater running for 4 hours uses 6 kilowatt-hours. At a rate of 12 cents per kilowatt-hour, that costs 72 cents. The math is always the same:
Watts on the label, divided by 1,000, times hours of use, times your rate per kWh, equals cost.
That formula is the single most useful thing in this module. Once you can run it, you can look at any appliance in your home and estimate what it costs to operate. The reading walks through several examples, including the appliances that surprise most people: anything that makes heat (space heaters, water heaters, dryers, ovens) draws far more power than anything that computes or lights.
The household that can calculate what a device costs to run will never be surprised by a utility bill again.
Your meter tells the story
Your electric meter records every kilowatt-hour that passes through it. Reading it yourself, before the bill arrives, tells you whether your usage is tracking where you expect or whether something has changed. The reading covers how to find and read both digital and analog meters, and the action step asks you to do exactly that: record the current reading, then calculate the daily cost of three appliances you use every day. That calculation becomes part of your Utility Profile.
The reading for this module
This is the core reading for the module. Take it with your earlier work beside you.
Read your meter and calculate three appliance costs.
Find your electric meter and record its current reading. Then check the wattage label on three appliances you use daily: a refrigerator, a space heater or air conditioner, and one more of your choice. Calculate how many kilowatt-hours each uses in a typical day using the formula from the reading. Record the results.