What Is Electricity?
A good definition of electricity is the flow of electrons. In addition, there are other terms used to define electricity. These include electric charge (the property of smaller pieces in an atom that gives rise to the production of an electromagnetic field), electric current (the flow of electric charge), electric field (the environment where the electric charges work), electric potential (the ability the electric field has to work), and electromagnetism (the relationship between electric charges in the magnetic field).
How Does Electricity Power Appliances?
In order to power anything, there needs to be a power source such as a fuel cell, solar cell, or a battery. This source must have both a positive and negative terminal so that the negative charged electrons will be forced to leave the negative terminal for the positive one. This flow of these electrons is guided by wires (copper, for example) to go where they are needed. The appliance is then placed in the middle of the circuit. A light bulb will then shine instantly and a tv, radio, or fan will work quickly after as well. The outlets are powered by electricity from solar energy, wind or hydro power.
Electrical current, or the number of electrons leaving and coming into different terminals, determines how much work is actually done or the type of appliance that can be powered by it. Obviously, the electrons only move where there is a force to move them. This is called voltage. The current is measured in Amperes and the voltage is measured in Volts, respectively. The rate of the current will also be affected by the resistance. If it’s high, the amount of work done and the current strength will be low. It’s wise to use thick wires in your electric circuit as a precaution.
Why Should I Know All This?
It’s a good idea to know the basics of how things work in case they break. That way you’ll have a better chance of knowing how to fix it.
Estimating Energy Usage
Figuring out how much electricity is being used by the various electronics and appliances will also show you how much money it’ll take to run them. There are several ways (listed below) to determine the amount of electricity used and therefore how much it will cost you.
- Take a look at at the Energy Guide label. It should give you estimates on how much energy and money it uses. However, not every home electronic or appliance will have an Energy Guide.
- Use an electricity monitor to get a reading of how much electricity is being used by an appliance.
- Calculate the annual energy consumption using a formula (given later).
- Install an energy monitoring system of your entire house.
Electricity Usage Monitors
These are both easy-to-use and inexpensive ($25-$50 at a hardware store). They can measure the electrical usage of any type of device that uses 120 volts. Unfortunately, bigger appliances (such as clothes dryers, central air conditioners, or water heaters) use 220 volts. It’s also always smart to read the user manual first.
To figure out how many watts a device is using, plug it into the monitor after plugging it into the outlet that the device is using. This will display the number of watts being used. To see how many kilowatt-hours (kWh) it uses over a period of time, just leave it set up for that amount of time and check it out later.
These monitors are good for finding the kWh of the devices (like refrigerators) that don’t run all the time. In addition, some of these monitors allow you to put in the amount you are charged per kilowatt-hour. This way you’d get an estimate of the cost for the time it’s been plugged into the monitor.
Even when they are turned off, most appliances still use a little bit of stand-by power. These are “phantom loads” and happen in most electrical appliances such as televisions, computers, stereos, and kitchen appliances. This will add a few watt hours to the energy consumption. The monitor can track this too though. If you want to avoid this, you can simply unplug the appliance or plug it into a power strip and shut that off when you’re not using the appliance(s).
How To Calculate Annual Consumption and Costs
Here are the steps to figure out both the energy consumption of a device and the cost to operate said device.
- Estimate the number of hours per day that an appliance was used (there are two ways to do this).
– Get a rough estimate based on how many hours you know you use something per day. For appliances that run periodically, such as a refrigerator, take the number of hours of operation and divide it by three. This will give you the amount of time it’s actually running at its maximum wattage.
– Keep a log of the time you use a certain appliance for. This works well for tracking the time you use the microwave, computer, television, or a light in a room or outside.
2. Figure out the wattage of the product (there are three ways to do this).
– Most appliances have their wattage stamped on either the bottom, back, or the nameplate of the device. Remember that this is the maximum power drawn. That means that the products use a range of settings depending on how they’re being used. For example, a radio playing on a higher volume will use more power than a radio using a lower volume.
– If you can’t find the wattage on an appliance, there is still a way you can figure it out. You find the electrical current draw (in amperes) and multiply it by the voltage being used by the appliance. As mentioned previously, most of them (in the United States) use 120 volts, while larger ones (clothes dryers, electric cooktops, etc.) use 240 volts. You can find the amperage on the unit in the place of the wattage, on the specification sheet, or the owner’s manual.
– You can also use online sources to get the usual wattage of specific products. A couple good ones are the Home Energy Saver (that has a list of appliances along with their estimated wattage and annual energy use as well as other characteristics) and Energy Star (which gives energy-use information on specific products that have earned the ENERGY STAR. Not only can you compare models, but you also can find a more efficient one than the one you have).
3. The daily energy consumption can be figured out with this formula:
(Wattage x Hours Used Per Day) ÷ 1000 = Daily Kilowatt-hour (kWh) consumption
4. The annual energy consumption can be found using this formula:
Daily kWh consumption x number of days used per year = annual energy consumption
5. The annual cost can be discovered by this formula:
Annual energy consumption x utility rate per kWh = annual cost to run appliance
Whole-House Energy Monitoring Systems
For more detailed information on how much energy your home is using, including the 240-volt appliances, get a whole-house monitoring system. These systems may have different features and prices. The cost and complexity depends on how many circuits you want to monitor, the level of detail of the data you want, and the features that will be available to you. Some of these will be installed right into the main breaker in your house and it’ll be required that an electrician put it in. Some of these devices can connect with the wireless network of your home which means the data can be viewed from a computer or phone. Still others use display screens.
Not only do they give you info on how much energy your appliances are using, they also show you when and where you’re using the most energy. This will help you find ways to reduce the usage and cost of the electricity to run your “devices.”