Glossary | ResEPA

Reference Information

This Page contains a list of supplemental information.

While it contains links to other pages on this platform, you should understand that one may press the browser Back button to return to a prior web page.

Measuring Energy - Kilowatt

A kilowatt-hour is a unit that measures how much electrical energy is used over time. Let's break it down:

First, a kilowatt (kW) is 1,000 watts

A kilowatt-hour is how much energy you use when you run something that uses 1 kilowatt (1,000 watts) for one hour

A 100-watt bulb running for 10 hours would use 1 kilowatt-hour (because 100 watts × 10 hours = 1,000 watt-hours = 1 kWh)

Here are some helpful analogies and examples ...

Device charging:

Charging your phone typically uses about 0.005 kWh per charge. This means you could charge your phone 200 times with 1 kWh

Home activities:

Running a window AC unit for 1 hour ≈ 1 kWh

Using a microwave for 1 hour ≈ 1.2 kWh

Playing video games on a gaming console for 10 hours

≈ 1 kWh

The energy in 1 kWh could:

Toast about 160 slices of bread
Run a ceiling fan for about 24 hours
Power a TV for about 10 hours

You can typically see the power requirements because it should be written on the device itself, either on a label or stamper printing.

Megawatt

A megawatt-hour is 1,000 kilowatt-hours, or 1,000,000 watt-hours.

It's such a large unit that it's typically used for:

- Measuring industrial power use
- Tracking power plant production
- Calculating city power consumption

Here are some relatable examples of what 1 megawatt-hour can do ...

Home Usage:

- Power an average American home for about 1 month
- Run an electric oven continuously for about 40 days
- Keep a central air conditioner running for about 10 days straight

Electric Vehicles:

- Charge about 12-14 Tesla Model 3 cars from empty to full
- Drive an electric car approximately 3,000 miles (roughly the distance from New York to Los Angeles)

Entertainment & Technology:

- Power a large movie theater for about 2-3 days
- Keep 1,000 laptops running for about 10 hours
- Run a gaming PC continuously for about 500 days

Industrial Examples:

- Run an industrial freezer for about 2 weeks
- Power a small factory for one day
- Keep a medium-sized office building running for about 1-2 days

Fun Fact: A typical wind turbine, when running at full capacity, produces about 2-3 MWh per hour!