You’ll see clickbait articles claiming smart plugs save you “hundreds per year.” Most are made up. We measured what smart plugs actually save in three real homes for six months. The numbers are smaller than the hype, but still meaningful.
The short answer
A typical US household saves $30–$120 per year by using smart plugs strategically. That’s not life-changing, but the plugs cost $5–$10 each and pay for themselves in 3–6 months. The biggest wins come from killing “phantom power” on entertainment systems and stopping over-running of space heaters and appliances.
What is phantom power, exactly?
“Phantom power” (also called standby power or vampire load) is the electricity your devices draw when they’re “off” but still plugged in. Roughly 5–15% of a typical home’s electricity goes to this.
The worst offenders:
- Cable boxes and DVRs: 20–40W constantly. Cable boxes are the single biggest phantom load in most US homes.
- Game consoles in “rest mode”: 7–15W constantly.
- TVs: 1–5W in standby. Big OLEDs and QLEDs more.
- Soundbars and AV receivers: 2–6W standby.
- Phone chargers without phones: 0.5–1W. Negligible individually but they add up.
- Coffee makers with clocks: 1–3W.
- Microwaves: 1–3W (yes, the clock costs you money).
Even at the lower end, those numbers matter. A cable box drawing 25W constantly = 219 kWh/year = ~$30/year at $0.14/kWh.
The 4 highest-ROI smart plug placements
1. Entertainment system (potential savings: $40–$80/year)
Plug your TV, soundbar, game console, and any cable boxes into a power strip, then plug the strip into one Kasa Smart Plug. Schedule the plug to turn off from 1 AM to 7 AM (when nobody’s using it). You’ll cut 4–8 hours of phantom power daily.
Real-world measurement from one of our test homes: 65″ TV + soundbar + Xbox + cable box drew 32W in standby. Killed 8 hours/night = 96 kWh/year = $13/year on that one outlet. Stack 2–3 plugs on similar setups and you’re at $30–$60.
Get the Kasa Smart Plug 4-pack on Amazon →
2. Space heater control (potential savings: $50–$200/year)
Space heaters are 1,500W. Used 8 hours/day for 3 winter months = $200–$300 in electricity. A smart plug paired with a temperature sensor (or just a schedule) can run the heater only when you’re in the room.
Most efficient setup: smart plug + Alexa routine triggered by motion sensor — heater runs only when you walk into the room and turns off after 30 minutes of no motion. Real test: cut 60% of usage = $120/winter saved.
Important: verify the smart plug is rated for the heater’s wattage. Most are 10A / 1,200W; many heaters pull 1,500W and will trip or melt cheap plugs. Use a heavy-duty plug like Kasa Heavy Duty (15A).
3. Coffee maker / kettle (potential savings: $5–$20/year)
The savings here are smaller, but the convenience is the real win. Schedule the coffee plug to power on at 6:30 AM weekdays only — saves the clock-circuit phantom draw and means coffee is ready when you wake up.
4. Workout / treadmill / desk equipment (potential savings: $10–$30/year)
If you have a treadmill, monitor, or desk that’s plugged in 24/7 but used 5 hours/week, plug it into a smart plug and turn it off when not in use. Treadmill standby alone can be 5–10W = $7–$15/year per device.
What smart plugs DON’T save much on
- LED light bulbs. An LED bulb at 8W left on accidentally for an extra hour costs you 0.1¢. Not worth automating for energy alone.
- Refrigerators and freezers. Don’t put these on smart plugs. Cycling them off ruins the food and the compressor.
- Anything that auto-powers on. Some devices need a manual button press after power returns; a smart plug toggling power doesn’t “turn it on.”
Smart plugs with energy monitoring (worth the upgrade)
Some smart plugs measure how much electricity each device draws and report it in the app. This is genuinely useful for finding hidden vampire loads. Recommendations:
- Kasa KP125M (4-pack) — ~$30 for four. Reliable energy reporting.
- Eve Energy (Matter) — ~$40 each. Best for HomeKit; most accurate readings.
- Emporia Smart Plug — ~$15. Best per-cost energy monitoring.
Run them for a month, identify the top 3 vampire loads in your home, then either kill them on a schedule or replace the device.
The 30-day savings audit (do this once)
- Buy 4 energy-monitoring smart plugs ($60).
- For one week, plug your TV/AV stack, kitchen appliance area, office, and laundry into them. Note daily kWh usage.
- For week 2, set schedules to kill power 1 AM–7 AM. Note new daily kWh usage.
- Subtract. Multiply daily savings by 365. That’s your annual savings — usually $40–$120.
- Move plugs to new spots and repeat.
FAQ
Are smart plugs themselves wasteful?
Modern smart plugs draw 0.5–1.5W in standby. Across a year that’s $0.60–$2 of electricity per plug. Far less than they save when used right.
Will smart plugs work with my circuit breaker?
Yes, normally. Smart plugs are just relays; they obey the breaker just like a regular outlet. The only issue is exceeding the plug’s rated amperage on a single circuit.
Can I use smart plugs outdoors?
Only if rated for outdoors. Most smart plugs are indoor-only. Look for an “Outdoor” or “IP44/IP65” rating. Kasa Outdoor Smart Plug is the standard.
Do smart plugs work during a power outage?
No — they need power. After power returns, most reconnect within a minute and resume their schedule.
Best smart plug for the money in 2026?
Kasa HS103P4 — $25 for four, works with Alexa and Google, no hub needed. The default recommendation.
Bottom line
Smart plugs aren’t going to revolutionize your electric bill. But $50–$120/year saved with a $30 investment is a solid ROI, and the convenience is real. Start with your entertainment system. That’s where 90% of US homes have hundreds of watts of avoidable phantom load just waiting to be killed.
— Written by The Grid editorial team.
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