Saving Electricity? Saving money? Parasitical Energy use?

One of the easier methods to save money, is to cut your energy consumption…  But beware, this is an area of diminishing returns…  Yes, automating your water heater, to turn off the heater when not in use will save a bit of power, but you end up having to wait for the Hot Water…  Instead a Tankless hot water heater might be a better choice…

Also, all the Automation devices have a slight power draw…  But more on that later in this page..

Identify your Power Usage

First, you need to find how much energy an item is using. For most devices you can just look at the label!Nearly everything you can plug into the wall has a label that says how much electricity it uses. (It may be printed directly into the plastic or metal.) You may have to hunt for the label. It’s often on the bottom or side of the device, or possibly where the power cord enters the unit. If the device is powered with an AC/DC adapter, the electrical rating is usually listed on the adapter itself.

If the label only gives the number of amps and not the number of watts, then just multiply the amps by 120 to get the number of watts. (Amps x Volts = Watts, and most U.S. electricity is 120 volts. So a hot plate that uses 6 amps uses 6 x 120 = 720 watts. Most other countries use 240 volts instead of 120, so outside of North America and Japan use 240 instead of 120 in your calculations.) Note that if a device is powered by a transformer (one of those great big plugs), then the transformer has converted the electricity from AC to DC, so you need to multiply by the DC voltage, not the AC voltage of 120. For example, if the device says “INPUT 9V, 0.5A”, then that’s 9 volts x 0.5 amps = 4.5 watts.

You may have noticed that appliances may be labeled 110, 115, or 120 volts. Appliances are actually designed to accept a range of voltages, between 110-120 volts, and the exact voltage coming out of your electrical socket can vary depending on conditions at the power plant and in your own home. Let’s just agree that when we say 120 volts, we understand that it’s actually a range from 110-120. And just use 120 for your calculations (unless you’re outside of North America or Japan, in which case you probably have 240 volts).

Your device might actually list a huge voltage range, like 100-240V. That just means that it will work with any country’s voltage. For your calculations, use the voltage for the country where you’re plugging the device in.

Some important caveats:

  1. The amount of electricity listed on the label is the largest amount that the appliance will ever use. For example, a 300-watt refrigerator will only run at 300 watts when the compressor’s running (which is when it makes that humming sound, indicating that it’s actually chilling the air inside). Most of the time the fridge just sits there, using only 5 watts or so for its electronics. If the amount of work done by a device varies up and down, then so does its energy use. (e.g., a stereo that can be turned up or down, an oven that can be set at various temperatures, a fridge that sometimes runs and sometimes doesn’t, a computer that sometimes spins its various drives and sometimes has to use more of its brainpower, etc.) The label on computers is particularly useless; a computer labeled at 300 watts probably uses only about 100. In just a bit we’ll cover how to measure the actual amount of electricity being used by a device.
  2. Many consumer items are advertised according to their power output, not input.That means the stereo that says 30 watts on the box might actually need 50 watts to make 30 watts of sound (assuming the volume was cranked), and your 900-watt microwave oven might actually use 1400 watts (on its highest setting). That’s because all electrical devices are inefficient — they have to use some extra energy to do what they do.
  3. Knowing how much electricity a device uses at a given moment doesn’t tell you how much it’s using in a month, because it’s probably not running 24/7 (and if it is running 24/7 like a fridge, it’s probably not using the greatest amount of electricity, as we discussed earlier). To measure how much electricity something uses for a certain period (like a week or a month), you can use a watt-meter.
  4. Some devices use a small amount of electricity even when they’re not on. For example, VCR’s and microwaves draw a small amount to power the time display. This amount is often 5 watts or less. Devices which run off transformers also draw a small amount of power.


And of course, electricity consumption of a device varies from brand to brand, and condition to condition.

Electrical usage of household items


Here are some examples of the range of nameplate wattages for various household appliances:

  • Aquarium = 50–1210 Watts
  • Clock radio = 10
  • Coffee maker = 900–1200
  • Clothes washer = 350–500
  • Clothes dryer = 1800–5000
  • Dishwasher = 1200–2400 (using the drying feature greatly increases energy consumption)
  • Dehumidifier = 785
  • Electric blanket (Single/Double) = 60 / 100
  • Fans
    Ceiling = 65–175
    Window = 55–250
    Furnace = 750
    Whole house = 240–750
  • Hair dryer = 1200–1875
  • Heater (portable) = 750–1500
  • Clothes iron = 1000–1800
  • Microwave oven = 750–1100
  • Personal computer
    CPU – awake / asleep = 120 / 30 or less
    Monitor – awake / asleep = 150 / 30 or less
    Laptop = 50
  • Radio (stereo) = 70–400
  • Refrigerator (frost-free, 16 cubic feet) = 725
  • Televisions (color)
    • 19″ = 65–110
    • 27″ = 113
    • 36″ = 133
    • 53″ – 61″ Projection = 170
    • Flat screen = 120
  • Toaster = 800–1400
  • Toaster oven = 1225
  • VCR/DVD = 17–21 / 20–25
  • Vacuum cleaner = 1000–1440
  • Water heater (40 gallon) = 4500–5500
  • Water pump (deep well) = 250–1100
  • Water bed (with heater, no cover) = 120–380

How Can Home Automation help save Energy?

  • Home Automation can save you money, but unless the device is horrible inefficient, this savings will be over long period of time.
  • Concentrate on the “big-ticket” items first, items that have the most energy draw, since they will return the most savings to you.
  • Beware Diminishing Returns, as you find and address the “big-ticket” items, you will be eventually reach devices that are lower draw.  Make sure that they need to be addressed, after all the Home Automation hardware has a ~1 Watt draw, so if the item only draws a few watts, it might be cheaper to not address the issue.
    • Alternatively, see if you can gather many of the transformer powered devices together, and automate the power strip that they are plugged into.
  • Take a look at your usage patterns, see what needs to be addressed?
    • For example, do people forget to turn off certain lights?  If so, setup a timer that activates when the light is turned on, when the Timer expires, turn off the light via the Home Automation software.
    • Do certain devices only need to be turn on at a certain time?  And turned off later?  For example, a Child’s night light?  (With Indigo, turn on 30 minutes before sunset, and turn off, half an hour after sunrise.)
    • If you are not using CFL (Compact florescent Lights), can you run the bulb at a dimmer setting?  If so, do so.
    • Do you have a Mud Room, Foyer, etc?  By using either a motion sensor, or a door sensor, you could have your lights in that room turn on when the door is opened, and turn off after a few minutes (e.g. 7 minutes) after you have left the area.
    • Do you have a Geothermal Heater?  Whenever the Geothermal unit runs (either AC or heat), it dumps the excess heat from the Geo unit into the water heater, so when the Geothermal unit turns on, have an Insteon device turn off that water heater and then turn it back on within a certain period. If the Geothermal runs again before that “time to off” expires, it resets the water heater timer. During the extreme hot and cold days when the Geothermal unit runs constantly, the water heater never turns on.
  • Remember, the number one goal of Home Automation is not necessarily to save money, but to make your daily activities easier, more productive, and smarter!
  • When you open a door, why shouldn’t the room/home automation turn on the lights for you?
  • Why shouldn’t you be alerted when an outside door is opened?
  • etc…etc…

Estimated Energy draw of Insteon Hardware

This has been difficult, since Smarthome has not specified what the energy draw is of the Insteon devices….  And their draw is so low, that it is hard to get an exact reading…

  • The Dual Band Lamplinc’s seem to draw roughly 1 Watt or Less of power.  (1 Volt-Amphere, 0Watts, Power Factor of .8)
  • Dave Houston did a long-term Kill-A-Watt measurement of a variety of SmartHome devices
    • AM486 0.4W  (X10 Appliance Module)
    • LM465 0.5W  (X10 Lamp Module)
    • TM751 1.2W  (X10 Appliance Module / Radio Transceiver)
    • RR501 1.4W (X10 Appliance Module / Radio Transceiver [16 device])
    • CM11A 1.3W  (X10 Computer Interface)
    • CM15A 0.93W  (2004 X10 Computer Interface with Integrated RF transceiver)
    • 1132B 1.2W     (SmartHome’s PowerLinc Controller for X10)
    • 2412S 0.9W    (Smarthome’s PowerLine Modem for Insteon/X10)
    • 2414S 0.9W    (Smarthome’s PowerLine Controller for Insteon/X10, with integrated Clock for Stand-Alone mode)
  • So the 2412S & 2414S seem to draw roughly .9 Watts, the non-dual band lamplinc draw approx. 1 Watt, and the dual band lamplinc draw “supposedly” 0 Watts, but probably less than 1 Watt, and a rounding error… (Kill-A-Watts are supposed to be accurate to roughly 1 Watt, but….)
  • So, the evidence suggests that the modern unit would draw roughly 1 Watt, after all the X10 units are older technically and generally less energy-efficient, and out of 9 units only 4 are above 1 Watt, so roughly 60% are under 1 Watt…