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Part II: Conservation FirstChapter 3. Seal, Insulate, and Cover

Phantom Loads and Efficient Lighting

Finding devices that draw power while idle, and lighting changes that are worth doing first.

Difficulty
Beginner
Cost
Under $30
published

A phantom load is electricity used while you think the device is off. A glowing display, a warm charger brick, a cable box that never sleeps, and a game console waiting for a remote are the usual examples. Each one is small. A cluster of them runs all year, which is why they show up in the flat part of the electric bill rather than in a winter spike.

They are rarely the largest line on the bill. Heat, hot water, and cooling still win in most houses. Measure before you reorganize the living room around power strips. The bill baseline tells you whether idle watts are even visible next to an electric water heater. The PV sizing guide should use the consumption you still have after the obvious waste is gone.

Difficulty

Level
Beginner
Time
An evening with a plug-in meter
Skills
Reading watts and leaving the important appliances alone

Cost estimate

Under $30

A plug-in watt meter is the useful purchase. A switched power strip helps if several idle loads share a spot. LEDs for the bulbs that burn for hours cost more only if you replace a whole house of closets you barely open.

Materials

ItemQtyNotes
Plug-in watt meter1Reads watts and, if you leave it, kilowatt-hours. A guess from a warm brick is not a measurement.
Switched power stripWhere a cluster sitsRated for the load. Not a home for a space heater.
LED lampsThe sockets you use for hoursMatch lumens to the old bulb, not watts. Note the color temperature you can live with.

What is worth switching off

Ten watts, all year, is about 88 kilowatt-hours. At a typical residential rate that is on the order of ten to fifteen dollars a year. Five such devices in one room justify a power strip, and a house full of them is worth an evening. A single phone charger is not.

Measure the device in the mode you actually leave it: "off" on the remote, not unplugged, unless unplugging is the habit you will keep. Write watts. Anything under a watt can stay. Anything that must stay on is not a phantom load. That list includes a refrigerator, a freezer, a sump pump, a medical device, a modem you need, furnace controls, and hardwired smoke and carbon monoxide alarms.

Printers, extra monitors, stereo amplifiers, and set-top boxes are the usual wins. A computer that you set to sleep is a smaller load than one you leave awake to avoid a thirty-second boot.

Lighting that matters

Replace bulbs by hours of use. A kitchen and a living room that are lit every evening pay for an efficient lamp. A closet you open with a switch for a minute does not. Look at lumens for brightness and at color temperature if the room feels harsh. A lower wattage that is too dim gets replaced with the old lamp, and the project fails.

Turn the lights off when you leave. That still beats any bulb technology. Outdoor lights on all night are a larger load than a living-room lamp, and they may be doing a security job. Put them on a motion sensor or a switch you control rather than defeating them blindly.

Idle watts add up all yearA row of small always-on loads beside a meter. One larger bar is a device that is actually doing work.Idle loads, all nightA real taskMeasure the idle watts. Do not guess from the glow of a display.
Small idle loads run all night. The tall bar is a device that is actually working. Measure before you treat them as the same problem.

  1. Walk the house at night

    Note what is lit or warm while you are asleep. Then measure those plugs. Skip the refrigerator.

  2. Group the real idle loads

    One switched strip for the television cluster. Leave alarms, pumps, and medical gear on their own circuits.

  3. Change the bulbs you use for hours

    Match brightness. Leave the closet alone until the rooms you live in are done.

  4. Check the bill, not the feeling

    A month later, compare kilowatt-hours with the baseline. A warm winter or a houseguest will lie to you if you only watch dollars.

Further reading

These links go to outside sources. This book cites them by link and does not copy their words or pictures.

General education, not a permit or a stamped design. Follow the safety note in the guide, read the safety disclaimer, and hire a licensed trade when the work requires one.