The Energy Audit-Plug In Loads

A plug-in load is any electrical device that uses electricity that is not heating (including water heating), cooling or refrigeration.  These plug-in loads account for approximately 20 percent of a home’s electricity use and include devices that use some electricity, even when the device is off, (known as a phantom load).  A recent study suggests that 30 percent of the energy used by plug-in loads is wasted.  In this week’s blog, I will be discussing strategies in reducing an electricity bill.

There are some household appliances that use large amounts of electricity, some operate occasionally, and some continuously.  A coffee maker is an example of an appliance that can operate continuously.  Certain models are designed to brew a cup of coffee instantly and operate like a mini-water heater.  I occasionally see coffee makers turning on and off when testing a homes electrical service panel.  An appliance that operates occasionally would be a toaster.  The toaster in my home uses 900 watts of power, (which would cost around $.10 per hour), but are only one for a few minutes per month.

A typical plug-in load. How much energy do these use? Testing will tell you.

I am often asked about televisions, DVD players, satellite or cable boxes and audio equipment related to the entertainment systems of a home.  All these devices use some power, even when you think they are off.  A television, for example, is waiting for a signal from a remote control, using a small amount of electricity.  The use of a smart power strip can help to reduce some of these phantom loads.  This style of power strip or surge protector works by automatically turning off equipment related to watching TV when the television is turned off.  There is no need for the DVD player to be on if the television isn’t on.  There are also a few select outlets on the power strip that remain on continuously.  Devices like a router or cable box that takes several minutes to reboot typically will be plugged into these areas.

Smart Strip, the top two plugs are always on, the third is the control plug, and the bottom four are all controlled.

Gaming systems, especially some of the older models can use larger amounts of electricity.  My recommendation is to save and turn off.  I’m occasionally in a teenager’s bedroom while conducting an energy assessment and the TV is off with the gaming system paused, still using electricity.  Also, streaming videos through a gaming system can use up to 10 times more electricity than watching on a computer or tablet.  FYI

Computers are similar to entertainment systems.  The use of a smart strip to turn off monitors and printers will help to reduce electricity costs.  At a minimum, I recommend setting up a computer’s sleep mode to automatically reduce power consumption of a computer when not in use.

Another device I am often asked about is a water treatment systems or water softeners.  This equipment uses very little electricity and needs to remain on to treat the water used in a home.

The use of smart devices are on the rise in homes.  These devices, switches, plugs, and light bulbs can be controlled by phones or other home automation equipment such as Alexa.  Voice control and even schedules and timers can help reduce electrical costs, but many of these devices are phantom loads.

As I said earlier, a phantom load is a small amount of electricity being used by an appliance that you think is off.  A good example is a cell phone charger. Most people leave the charger plugged into the wall, even after they remove the phone.  The power usage of the charger is very small, probably only adding pennies per year to your electric bill, but consider everyone in your community that also leaves their chargers plugged in.  This small device adds to the electrical demand for the utility company, which in turn can affect costs, and that’s just one small device in your home.  The best advice for phantom, and all plug-in loads for that matter is:

1. Unplug when not in use.
2. If you can’t unplug, use a power strip with an on/off switch or a smart strip.
3. If you can’t use a power strip, use a timer to automatically turn on and off devices.

How to test plug in loads.  There are a couple of ways to test electrical loads within a home.  One way is by testing inside the electrical service panel.  I don’t recommend this type of testing because of the danger of electrocution.  A simpler test can be conducted by using a recording watt meter.  My unit is a Kill A Watt recording meter which costs under $30.  A great tool for testing any 120 volt plug in appliance.  In my area, these units can also be checked out at a public library or sometime utility companies will borrow a unit to their customers.

My Kill-o-watt meter

There is at least one whole house metering tool that is available.  The unit is called TED, or The Energy Detective.  An expensive tool for testing household energy use.  The system is installed inside the home’s electrical service panel and can monitor single circuits, both 120 volt or 240 volt, or the entire electrical panel.  My experience with this system is installation requires working inside an electrical panel which should be done by a qualified professional.  I had an older model that took some time to set up and at times could be finicky, but when it was operating correctly, supplied me with both real time and saved electrical usage data.

Calculating electricity costs.  Converting electrical usage to cost is done by multiplying kilowatts being used by the device by the cost of power, roughly $.12 in my area. 1 kilowatt is equal to 1000 watts.  Using a 100-watt light bulb as an example, 100 watts is 10% of 1 kilowatt. .1-kilowatt x $.12 = $.012.  The cost to operate the light bulb is 1.2 pennies per hour, $.29 per day, or $8.70 per month if allowed to run continuously.  Some electrical devices do not list wattage on a nameplate.  They will list voltage, which is typically either 120 or 240, and amperage.  Wattage can be figured by multiplying the voltage times the amperage. A TV that draws 2.5 amperes at 120 volts will use 300 watts. 2.5 amps x 120 volts = 300 watts. 300 watts = .3 kilowatts x $.05 = $.015 per hour.

My blog posting, The Energy Audit-Ohms Law has more information on electricity and electrical calculations and the posting The Energy Audit-Energy Costs has more info about household energy use.  Read more there.

Plug in loads, some people are very conscious and turn everything off, others just pay for the added usage. Just being aware is half the battle…until next week.

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