Solar Energy If you take a closer look at your electricity bill, you will notice a number showing how many kilowatt-hours you use each month. Many of us don’t pay attention to it, but learning about it can help you save energy, lower your electricity bill, and save money. So, what is a kilowatt-hour? And more importantly, how can you use this information to your advantage?

Let’s find out!

### Kilowatt-Hours Explained

A kilowatt-hour (kWh) is a way of measuring how much energy you are using in an hour. Although it might sound like it does, this number doesn’t actually show how many kilowatts you spend per hour. So, a kilowatt-hour is only a unit of measurement that matches the amount of energy you would use by keeping a 1,000 watt appliance on for an hour.

For example, if you left a 100-watt bulb on for 10 hours, it would use one kilowatt-hour of energy. On the other hand, a 2,000-watt appliance would spend 1 kWh of energy in only half an hour.

It’s not easy to be precise since similar devices can have different wattages, but here are some examples of 1 kWh usage.

• Baking in a 2,000-watt oven for thirty minutes
• Ironing with a 1,000 watt iron for one hour
• Watching a 280–450 watt plasma TV for around three hours
• Having a 200–400 watt fridge on for three hours
• Using a 20–50 watt laptop all day

### The Difference Between Kilowatt and Kilowatt-Hour

Kilowatt and kilowatt-hour sound similar but mean different things. In metric, a kilo means 1,000, so a kilowatt is 1,000 watts. Therefore, a kilowatt is a measure of power that equals 1,000 watts. On the other hand, a kilowatt-hour is the amount of energy a certain appliance needs to work for one hour. ### You Can Calculate How Many kWh Your Appliances Use

In most cases, heating or cooling your house uses the most energy. However, around 20% of your bill goes to your appliances. So, to see which devices use the most electricity, you need to go through a few simple steps.

1. Make a list of major appliances, such as a washing machine, dishwasher, TV, etc.
2. Check the tag on those appliances and find the number of watts they consume.
3. Write down the number of hours you use them each day.
4. Calculate the kWh for each device and appliance like this:

Appliance: Refrigerator, 300 watts
Hours per day: 24 hrs
Formula: 300 watts X 24 hrs = 7,200 watt-hours per day
7,200 watt-hours per day /1,000 = 7.2 kWh a day
7.2 kWh a day X 30 days = 216 kWh a month

Or, you can use this calculator and make things easier for yourself.

### How Many kWh Should You Be Using Per Month?

The amount of kWh you use each month will depend on various factors. Some of them include:

• How big your home is
• How many family members live there
• The quality of your house’s insulation
• How many appliances you use, and how old they are
• The way you heat and cool your house