Watts, Amps, Volts, and More: Energy Terminology for Homeowners

Electricity is a big part of our everyday lives. We charge our many devices, dry our hair, wash our clothes, heat our water, and light our rooms, all thanks to electricity. If you’re like me, you probably use electricity without thinking about wattage, amps, or volts, but those three energy measurement terms are a big component of your electrical system, and understanding them will in turn help you interpret your electrical bill.

In this article, we will take a look at basic electrical terminology and how it applies to your home and to your wallet.

Electric Terminology

Before going into detail about how electricity works in your home, it’s important to first understand what exactly electricity is. Electricity’s basic components comprise power (measured in watts), voltage (measured in volts), current (measured in amps), and resistance (measured in ohms).

Examples of how electricity works often describe water flowing through pipes. In this example, watts are the power or energy the water provides, volts are the pressure of the water in the pipes, and amps are how much water is flowing through the pipes.

Definitions of watt, volt, and amp

A watt measures the amount of energy consumed or generated. Wattage is determined by multiplying voltage by amperage.

A volt measures voltage, which is electrical pressure, or the potential energy between two points.

An amp is the unit of measurement for amperage, which is electrical current, or the rate at which electricity is flowing.

Electricity Use in Your Home

We might know what watts, amps, and volts are now, but how do they apply in the home? Let’s take a look.

Light bulb wattage

Most people only think about watts when it’s time to buy a new light bulb for a fixture. Different fixtures have different maximum wattage ratings. In other words, fixtures have a limit to the amount of energy they can safely use. Exceeding this maximum rating increases the risk of fire.

Watts do not indicate the brightness of a light bulb, so don’t be worried when you see fancy new LED bulbs with wattages that are much lower than you’re used to buying. Remember, watts measure the amount of energy consumed. Lower wattage is good. If your table lamp has a maximum wattage rating of 60W, then the 8.5W LED bulbs labeled as 60W replacement bulbs will work just fine and save energy.

Appliance wattage and voltage

Different types of appliances use different amounts of watts and run on different voltages. Larger appliances use more watts and some run on a higher voltage. That’s why some appliances, such as ovens, are plugged into outlets that look different from the average wall outlet. Typically outlets in a home can handle 120 volts, and the outlets for bigger, heavy-duty appliances can handle 240 volts.

Energy.gov has a handy tool for calculating the cost of running appliances throughout the year. Simply enter the wattage of the appliance and the amount you use the appliance. This tool can also help you compare models with different wattages when you’re shopping around for new appliances (and remember, less energy usage will result in lower electrical bills).

Electric service panel amperage and voltage

Standard electrical service panels in new homes today provide 200-amp service. This means that up to 200 amps can flow through the main breaker of the panel without tripping the breaker.

Each individual circuit breaker in an electric service panel has a different amperage rating. Single-pole circuit breakers are the most common type of breakers. They supply 120 volts and are rated for 15 to 20 amps. Double pole circuit breakers are usually dedicated for larger appliances. They supply 240 volts to a circuit and are rated to handle anywhere from 15 to 200 amps, although most range from 30 to 50.

How to Read Your Electricity Bill

Most energy bills display monthly energy usage in the form of kilowatt hours, or kWh. Kilowatt hours are determined by multiplying kilowatts used by the hours of use (a kilowatt is 1,000 watts). Your energy company multiplies kilowatt hours by a certain rate, and the result is the amount charged on your bill.

Tips on lowering your energy usage

1. Buy more energy-efficient light bulbs. New LED lights have much lower wattages, which means they use less energy. You have light fixtures all over your house. Replacing all the bulbs may seem like a daunting task, but it will save energy to convert old filament bulbs to new LEDs.

2. Unplug appliances you’re not using. Some appliances draw energy while plugged in, even when they’re not actively in use. For your entertainment system or other areas where it’s difficult to unplug everything you’re not using, look into getting an advanced power strip. These are designed to keep your electronics from using power while they’re off.

3. Upgrade to more energy-efficient models when it’s time to replace big appliances. Look for the Energy Star label for products that are designed to meet certain efficiency standards that are above the federal minimum standards. Also pay attention to the EnergyGuide label, a black-and-yellow label that displays information about energy usage.

4. Reduce use of high-wattage appliances. A/C systems, dryers, and water heaters use a lot of watts, so if you can cut down on your use of those three appliances you can cut back a significant amount of kilowatt hours on your bill.