How do kilowatt hours work?

Question

I will soon be calling my local electric company to set up electicity in an apartment I'll be moving to. I was told I'll be charged by kilowatt hour. So what is a kilowatt hour? How much is a kilowatt hour? For example, I have a toaster oven that uses 700 watts of power. So how many kilowatt hours is that?

Answer 1

The kilowatt-hour is a unit of energy. It is abbreviated kWh, and represents power (kW) consumed over time (hours).

Electric rates will vary by region, and can run between 2¢ and 15¢ per kWh or even higher. For discussion purposes, I will assume a rate of 10¢ per kWh. This can also be displayed as $0.10 / kWh

Your 700 watt toaster oven is 0.7 kW. If it runs for one hour, then you have consumed 0.7 kW x 1 hour = 0.7 kWh.

If the toaster oven runs for 15 minutes, that is .25 hours.
0.7 kW x .25 hour = 0.175 kWh.

You receive a bill once a month, so the electric meter keeps track of the kWh usage over the month.

In my house the TV seems to be on at least 10 hours every day. Assuming the TV uses 200 watts, the monthly usage would be:

0.2 kW x 10 hours/day x 30 days = 60 kWh
At a rate of $0.10 per kWh, this amounts to $6.00 per month.

A typical apartment might use around 200 to 400 kWh per month. (excluding electric hot water and electric heat)

Answer 2

electric companies charge in kiloWatt hours.

let assume $0.10/kwh (kilowatt hour) as the rate

toaster is 0.7kW (700 Watts) and if left on for one hour, would be 0.7 kWh. your bill would be $0.07 ($0.10 x 0.7kWh).

So, it is how much power you consume multiplied by how much time, multiplied by the rate charged.

Answer 3

One watt-hour is the amount of (usually electrical) energy expended by a one-watt load (e.g., light bulb) drawing power for one hour.

Laymen and utilities tend to use watt-hours to measure energy rather than joules, for reasons of convenience and intuition. For example, a light bulb draws power (units of watts) over a certain amount of time, resulting in a net amount of used energy; a watt has units of energy-per-time, and an hour is a convenient unit for measuring time, so when multiplied together they produce a unit of energy called the watt-hour. The watt-hour is derived from the multiplication of the SI unit of power (watt) and a non-SI unit of time (hour).

Answer 4

the watt consume of a circuit is given by multiplying the tension and intensity needed for the circuit.