Standby Power: Finding the Devices That Use Electricity While 'Off'

Walk around most homes at night and you will see small lights glowing everywhere: on the television, the games console, the microwave clock, the router, phone chargers and speakers. Each light is a sign that the device is drawing some electricity even though nobody is using it. This is called standby power, and the broader category of electricity used by devices that are switched "off" but still plugged in is often called a phantom load or vampire load.

Individually, most of these devices use very little. Together, running twenty-four hours a day, every day of the year, they can add a meaningful amount to an electricity bill. The good news is that finding and cutting unnecessary standby use is easy, cheap and permanent.

What standby power is

Many devices keep part of their electronics running when switched off by remote or button, so they can:

• respond to a remote control;
• keep a clock or settings in memory;
• download updates or stay connected to a network;
• start up faster ("quick start" or "instant on" modes);
• charge batteries or power a transformer in a plug-in adapter.

Modern devices sold in many markets must meet limits on standby consumption, and recent appliances often use well under a watt in true standby. Older devices, devices in "networked standby", and some features such as quick start modes can use considerably more. Power adapters left in the socket after the phone or laptop has been unplugged usually draw only a tiny amount, but older ones can draw more.

Why it adds up

The key point about standby power is time. A device that uses only a few watts in standby does so for every hour it is not in use — often more than twenty hours a day. Over a year, a household's many small loads can combine into a noticeable total.

You can estimate the yearly consumption of any always-on load:

Watts × 24 hours × 365 days ÷ 1,000 = kilowatt-hours (kWh) per year

For example, a combination of devices drawing a constant 30 watts in total would use 30 × 24 × 365 ÷ 1,000 ≈ 263 kWh per year. Multiply by the price per kWh on your bill to see what it costs. The figure in your own home could be much smaller or larger; the only way to know is to measure.

Measuring with a plug-in energy meter

The most useful tool for this job is an inexpensive plug-in energy monitor (sometimes called a power meter or watt meter). It plugs into a wall socket, and the device plugs into it. A small display shows how many watts the device is drawing, and many models also total the energy used over time and estimate the cost.

To survey your home:

1. Switch the device off normally, with its remote or button, as you usually would.
2. Read the meter after a minute or two. This is the standby draw.
3. Note it down along with the device name.
4. Repeat for each device or each extension lead of devices.

Some energy suppliers, libraries and community energy groups lend these meters free of charge, so check before buying one.

If you have a smart meter with an in-home display, you can also look at your home's baseline consumption late at night, when everyone is asleep and nothing major is running. That figure is your household's "always-on" load. Switching things off one at a time and watching the display drop shows where the electricity is going.

The usual suspects

Devices that commonly have notable standby or always-on consumption include:

These are typical patterns; your own measurements matter more than any generic list.

What not to switch off

Some devices should stay on, or should be handled carefully:

• Fridges and freezers. Never switch these off to save standby power — they need constant power to keep food safe.
• Heating and hot-water controls, boilers and timers. Switching these off can disrupt programming and may affect frost protection.
• Smoke, carbon monoxide and security alarms, and any medical or assistive equipment.
• Internet routers, if household members rely on them for work, security cameras, phones or alarms. Some households choose to switch routers off at night on a timer; others need them on. Frequent power cycling is generally fine for most routers but check whether your internet service provider advises against it.
• Recording devices set to record programmes.
• Devices that need to install updates. Leaving computers and consoles fully off forever means they may update at inconvenient moments; allow them to update periodically.

Easy ways to cut standby use

Switch off at the wall

The simplest method costs nothing: switch devices off at the socket when they are not in use, especially overnight and when you are away. For devices clustered together, such as a television, console and speakers, plug them into one extension lead with a switch, so one flick turns them all off.

Make sure extension leads are not overloaded, are in good condition, and are never daisy-chained (one extension lead plugged into another).

Use standby savers and smart plugs

• Standby saver plugs and "master-slave" extension leads switch off accessory devices (speakers, consoles, set-top boxes) when the main device (the television) is turned off.
• Timer plugs can switch devices off at night automatically.
• Smart plugs can be controlled from a phone or set on schedules. They draw a small amount of power themselves, so they make most sense for devices with significant standby draw.

Change device settings

Many devices have settings that reduce standby use:

• Turn off "quick start", "instant on" or "fast boot" modes on televisions and consoles; startup will take a few seconds longer.
• Use energy-saving or eco modes.
• Enable automatic power-off after a period of inactivity.
• Set computers to sleep after a short idle period and to shut down at night.
• Reduce screen brightness, which also lowers active power use.

Unplug chargers

Unplug chargers once devices are fully charged. Not only does this cut small standby loads, but it is also good practice for safety.

Thinking beyond standby: always-on appliances

While surveying, you may discover larger always-on consumers:

• Old second fridges or freezers in garages, often half-empty and inefficient, can use far more electricity than all your standby devices combined. If you do not need one, emptying and switching it off — or replacing it with an efficient model — can make a much bigger difference.
• Aquarium heaters and pumps, dehumidifiers and towel rails run for long hours; check their settings and timers.
• Hot tubs and pool pumps can be major consumers; timers and covers help.

Safety considerations

• Do not switch off devices that need to stay on for safety or health reasons.
• Avoid overloading sockets and extension leads; check the maximum load printed on them.
• Replace damaged plugs, cables and chargers.
• Buy chargers and power adapters from reputable sources; cheap counterfeit chargers can be dangerous.

When you are away from home

Holidays and long weekends are a good opportunity to cut always-on loads to the minimum. Before you leave, switch off at the wall the television, games consoles, computers, printers, speakers, coffee machines and chargers. Decide in advance whether the router should stay on — for example, if you have security cameras, a smart thermostat or an alarm that depends on it. Leave the fridge and freezer running, and leave heating controls and hot-water timers in a sensible frost-protection or holiday setting rather than switching them off entirely in cold weather, since frozen pipes cost far more than a little energy.

Buying new devices with standby in mind

When you replace electronics, check the specifications for standby and networked-standby consumption, which are often listed in the manual or on the manufacturer's website. Look for automatic power-down features and an easy way to switch the device off completely. A device that is cheap to buy but draws a significant amount of power around the clock can end up costing more over its lifetime than a slightly more expensive, efficient one.

A one-evening standby audit

1. Borrow or buy a plug-in energy meter.
2. Starting in the living room, measure each device switched off by remote.
3. Write down any device drawing more than a watt or two.
4. Group devices on switched extension leads where it makes sense.
5. Change settings on televisions, consoles and computers to reduce standby.
6. Unplug unused chargers and devices you rarely use.
7. Check your smart meter's overnight baseline before and after to see the result.

The bottom line

Standby power is a small, constant drain that hides in plain sight. You will not transform your energy bill by unplugging a phone charger, but a careful audit — measuring what your devices really draw, switching off clusters of electronics at the wall, adjusting settings and dealing with any forgotten old fridge in the garage — can trim your household's baseline consumption for good, with almost no effort once the habits are in place.