Smart plugs save energy only when they cut power to devices that waste it in standby or run when nobody needs them. This post is for homeowners and renters who want lower bills and doubt the gadgets are worth the money. The plug itself draws about 0.5-2 W around the clock, so typical savings run from a few dollars to tens of dollars per year. On some devices, the plug costs you money.
Quick answer
Smart plugs help on high-standby gear like set-top boxes, game consoles and desktop setups, and on loads you forget to switch off. They rarely help on low-draw items. Measure the device first, then decide.
- Best for TV cabinets: one plug feeding the whole strip
- Best for finding waste: an energy-monitoring plug
- Best to skip: phone chargers and lone modern TVs
- A smart plug uses about 0.5-2 W itself. At 1 W that is roughly 8.8 kWh a year, or about $1.50 at 17 cents per kWh.
- Devices with 5 W or more of standby draw are the ones worth controlling.
- Realistic savings: about $3 to $25 per year per plug, depending on the device and your rate.
- Never put refrigerators, freezers, space heaters or medical devices on a smart plug.
- Use a plug with energy monitoring to measure first, then keep it where it pays.
- How do smart plugs save energy?
- Do smart plugs use electricity themselves?
- Which devices are worth putting on a smart plug?
- How much can you save, and how long is the payback?
- Which devices should never go on a smart plug?
- Do smart plugs with energy monitoring help?
- Do smart outlets save energy differently?
- Do Wi-Fi and hubs eat the savings?
- Buying checklist
- What do owners say?
- Frequently Asked Questions
How do smart plugs save energy?
They cut power to a device when you are not using it. A schedule, timer, motion trigger or “away” routine turns the plug off, and the device stops drawing standby power.
Standby power, often called vampire load, is the electricity gear uses while “off” but still plugged in. The U.S. Department of Energy says it can account for roughly 5-10% of residential electricity use. Lawrence Berkeley National Laboratory research has estimated a similar share, with an older figure of around 23 W per average home. ENERGY STAR also notes that many products keep using power when turned off.
A smart plug only saves energy in two cases:
- The device has real standby draw, and the plug cuts it.
- The device runs when it should not, like a fan, lamp or coffee maker left on.
If neither applies, the plug adds a small load and saves nothing.
Do smart plugs use electricity themselves, and how much?
Yes. Typical smart plugs draw roughly 0.5-2 W continuously to keep the radio listening and the relay ready. At 1 W that is about 8.8 kWh per year, roughly $1.50 at $0.17/kWh. At 2 W, double it.
Most top-ranking pages skip this. The plug’s draw comes straight out of your savings. A device with 1 W of standby gains nothing from a 1 W plug.
Wi-Fi plugs usually sit at the higher end of the range. Zigbee, Thread and Matter-over-Thread plugs are often lower, but the spec sheet or an energy-monitoring plug is the only way to be sure. Check the manufacturer’s standby figure before you buy.
Which devices are worth putting on a smart plug?
Devices with 5 W or more of standby draw, or that sit on all day for no reason. Modern TVs in standby often draw under 1-3 W, while some set-top boxes, game consoles in rest or instant-on mode, and audio gear can draw 5-15 W.
The table uses round, illustrative standby figures, not measurements of specific models. It assumes the device is fully off 24 hours a day, the best case. Net saving subtracts a 1 W plug (8.76 kWh, about $1.49 per year).
| Device | Typical standby (W) | Annual kWh if left on 24/7 | Annual cost at $0.17/kWh | Net saving after 1 W plug |
|---|---|---|---|---|
| Modern TV | 2 | 17.5 | $2.98 | $1.49 |
| Set-top box | 12 | 105.1 | $17.87 | $16.38 |
| Game console (rest mode) | 10 | 87.6 | $14.89 | $13.40 |
| Soundbar or audio gear | 5 | 43.8 | $7.45 | $5.96 |
| Inkjet or laser printer | 3 | 26.3 | $4.47 | $2.98 |
| Desktop monitor, speakers, dock | 10 | 87.6 | $14.89 | $13.40 |
| Phone charger, nothing attached | 0.5 | 4.4 | $0.74 | -$0.74 (loses money) |
The pattern is clear. Entertainment centers and desks pay off. Single low-draw items do not.
How much money can I realistically save per year, and how long is the payback?
Most households save about $3 to $25 per year per plug, so payback runs from several months to several years. Use this formula:
Annual saving = (standby W − plug W) × hours off per day × rate ÷ 1000 × 365
Then divide the plug price by the annual saving. The formula is a close estimate. The plug also draws power while the device is on, which trims the result slightly. All three examples assume $0.17/kWh and a 1 W plug.
- TV cabinet: TV (2 W), set-top box (12 W) and soundbar (5 W) on one strip total 19 W. Off 20 hours a day: (19 − 1) × 20 × 0.17 ÷ 1000 × 365 = about $22.30 a year. A $15 plug pays back in roughly 8 months.
- Home office: Monitor, speakers, dock and printer total about 10 W. Off 16 hours a day: (10 − 1) × 16 × 0.17 ÷ 1000 × 365 = about $8.90 a year. A $12 plug pays back in about 16 months.
- Game console: Rest mode at 10 W, off 20 hours a day: (10 − 1) × 20 × 0.17 ÷ 1000 × 365 = about $11.20 a year. A $12 plug pays back in about 13 months.
In a 40-cent-per-kWh state, multiply those savings by about 2.4. At 12 cents, multiply by about 0.7. Rates matter as much as the device.
Which devices should never go on a smart plug?
Anything where losing power creates a safety, health or cost problem. Standard US outlets and most smart plugs are rated 15 A at 120 V, or 1,800 W maximum. Many plugs carry a lower rating for certain load types, so read the label.
- Refrigerators and freezers: a power cut risks spoiled food, and compressors dislike rapid restarts.
- Space heaters and other high-wattage heaters: they can pull the full 1,500 W or more, which strains the relay and raises fire risk. Skip them.
- Medical devices: oxygen concentrators, CPAP machines and similar gear must never lose power by accident.
- Anything over the plug’s rating: window air conditioners, large power tools and dryers.
- Routers and DVRs on a schedule: a router loses connection, and a DVR can miss recordings or corrupt its drive.
- TVs and consoles that need updates: cutting power can mean slow boots, lost settings or failed updates.
Plug straight into the wall outlet. Never use an extension cord to add a smart plug, and never chain plugs. Call a licensed electrician if an outlet feels warm, loose or discolored.
Do smart plugs with energy monitoring help, and how do I use the data?
Yes, they are the best way to know if a plug will pay off. A monitoring plug shows live watts and cumulative kWh, so you can read a device’s real standby draw instead of guessing.
Move one monitoring plug around the house for a few days each. Check the TV cabinet, the desk, the garage freezer (monitor only), the old second TV. Owners often find an unexpected hog this way. Then buy plain plugs, or schedule the monitoring plug, only where the numbers justify it.
- Standby under 2 W? Skip the plug. Unplug it or leave it alone.
- Standby 2-5 W? Only worth it if it is on a shared strip or your rate is above 25 cents.
- Standby 5 W or more? Add a plug and schedule it for the hours you never use it.
- Device forgets settings, boots slowly or needs updates? Use its own deep-sleep setting instead.
- Device is a heater, fridge or medical item? Do not use a smart plug at all.
Do smart outlets save energy differently from plug-in smart plugs?
Not in how they save. Both cut power on a schedule or command. The difference is cost, wiring and convenience. An in-wall smart outlet draws about the same small amount as a plug, and it replaces a standard receptacle. That work is simple for experienced DIYers, but hire a licensed electrician if you are unsure. Renters usually cannot do it.
Is switching off at a smart plug better than standby mode or a plain power strip? Against standby, yes, when the device has real draw. Against a manual switch, a plain strip saves the same energy at no ongoing cost, but only if you remember to flip it.
| Option | Typical cost | Own draw | Convenience | Best use |
|---|---|---|---|---|
| Plug-in smart plug | Low | About 0.5-2 W | Schedules, app, voice | Renters, strips, single devices |
| In-wall smart outlet | Higher, plus install | Similar small draw | Hidden, no bulky plug | Homeowners, fixed spots |
| Advanced power strip | Moderate | Small, varies by model | Automatic, no app | TV and PC clusters |
| Manual switch or strip | Lowest | None | You must remember | Gear you use rarely |
Do smart plugs lose savings due to Wi-Fi and hub standby use, and how can I minimize it?
Yes, a little. The plug’s 0.5-2 W is the main loss. A hub adds more. A hub drawing 2 W costs about $3 a year at 17 cents per kWh (2 W × 8,760 hours ÷ 1,000 × $0.17).
To cut the loss:
- Use fewer plugs, each one on a strip with several devices.
- Pick models with a published low standby figure.
- Skip plugs on devices under 2 W of standby.
- Reuse an existing hub rather than adding one.
Buying checklist
- Rated 15 A / 1,800 W, with a safety listing mark on the label.
- Energy monitoring, at least for your first plug.
- Local control or Matter support, so it works if the cloud app goes away.
- A slim body that does not block the second outlet.
- Scheduling and “away” routines without a subscription.
- A published standby figure, if available.
What do owners say?
Owners like
- Energy monitoring revealed unexpectedly high-draw devices
- Scheduling lamps, fans and coffee makers is convenient and prevents forgetting to switch things off
- Voice and app control for hard-to-reach outlets
- Cheap and easy to install with no wiring, especially for renters
- Useful for remote reboot of routers or modems and for away-from-home control
Common complaints
- Savings are tiny, often a few dollars a year, so payback is slow
- Wi-Fi plugs drop offline or need re-pairing after router or app changes
- Cloud-dependent apps with account requirements, ads or discontinued support
- Bulky plugs block adjacent outlets
- Cutting power to TVs or consoles causes slow boot, lost settings or updates failing
Summarised from owner reviews and long-term user reports; individual experiences vary.
Frequently Asked Questions
How do smart plugs save energy?
They switch off devices that draw standby power or run when not needed, using schedules, timers or automation. The saving equals the device’s standby watts minus the plug’s own 0.5-2 W, multiplied by the hours it stays off.
Do smart plugs save energy reddit?
Reddit-style owner reports are mixed. People praise energy monitoring for finding hidden loads and scheduling for lamps and coffee makers. Many say the savings are only a few dollars a year. Plugs that drop offline or lose app support are common complaints.
Do smart outlets save energy?
They save the same way plugs do, by cutting power to what is connected. Their own draw is similar and small. Choose them for a clean look and fixed locations, and hire a licensed electrician if you are not sure how to install one.
Do smart plugs save energy?
Sometimes. They save on devices with 5 W or more of standby draw and on loads left running by mistake. On low-draw devices like modern TVs or phone chargers, the plug’s own use can cancel the saving. Measure first, then decide.
