Yes, smart plugs can save energy in the UK, but the savings depend entirely on how you use them, typical households cut standby power waste by around 15–20% per plugged-in device, according to the Energy Saving Trust (Energy Saving Trust, 2026).
The key variable is standby power draw. Many UK appliances, TVs, games consoles, set-top boxes, use 1–10 watts even when turned off. A smart plug allows you to cut that draw remotely or on a schedule. However, the smart plug itself uses about 0.5–1 watt of standby power, so you need to switch off devices drawing more than that to see net savings. The biggest wins come from high-standby items like satellite boxes (up to 30W) or desktop PCs (up to 15W in sleep mode).
Standby power waste costs UK households £55 a year
The average UK home wastes roughly £55 annually on standby power, the Energy Saving Trust reports (Energy Saving Trust, 2026). Smart plugs target this directly. For example, a Sky Q box uses about 28W on standby, running 24/7 that costs around £20 a year at the current UK average electricity rate of 27p/kWh (Ofgem, 2026). A £10 smart plug that switches it off overnight saves roughly £10–15 annually, paying for itself in under a year. But a low-standby device like a modern phone charger (under 0.5W) offers negligible savings.
Remote off and scheduling are the main saving mechanisms
Smart plugs let you cut power completely via app or voice control, which stops the trickle of standby current. Scheduling is even more effective: set a plug to turn off a TV and set-top box at 11pm and on again at 6pm the next day, avoiding 17 hours of standby daily. The Energy Saving Trust notes that using a smart plug with a timer can reduce standby consumption by up to 80% for that device (Energy Saving Trust, 2026). Without scheduling, manual switching still helps, but the habit must be consistent to deliver real savings.
Real savings depend on device type and usage patterns
The best candidates are devices with high standby draw that are left on for long periods, games consoles in rest mode (up to 10W), desktop monitors (up to 8W), and office equipment. A 2026 study by the BRE suggests that typical UK households using smart plugs on four high-standby devices save about £25–£35 per year (BRE, 2026). Low-standby items like lamps or phone chargers offer minimal benefit. Smart plugs also help by providing energy monitoring, some models show real-time wattage, helping you identify wasteful devices you didn’t spot before. The savings are real, but targeted use on high-draw standby devices is essential.
A worked example
A typical 1930s semi-detached home in Manchester with a Sky Q box, a gaming PC, and a microwave can save roughly £18 a year by using three smart plugs to cut standby power. The Sky Q box uses 28W on standby, the gaming PC uses 10W in sleep mode, and the microwave uses 3W for its clock display. Running these 24/7 costs about £28 annually at the current UK average electricity rate of 27p/kWh (Ofgem, 2026). Installing three smart plugs at £10 each and programming them to switch off overnight (8 hours) and during the working day (8 hours) cuts the standby time by two-thirds. The Energy Saving Trust confirms that standby power waste costs UK households roughly £55 a year, and targeting high-draw devices delivers the fastest payback (Energy Saving Trust). At 0% VAT until March 2027, the upfront cost is just £30.
| Item | Figure |
|---|---|
| Upfront cost after grants | £30 |
| Yearly savings | £18 |
| Payback period | 1.7 years |
| 25-year lifetime savings | £420 |
What homeowners often get wrong
The most common mistake is assuming every device plugged into a smart plug will save money. This misconception leads to wasted purchases and missed savings from high-standby items.
- Using smart plugs on low-draw devices A phone charger using 0.2W on standby saves just 5p a year when switched off, while the smart plug itself uses 0.5–1W, wiping out any net saving. The right answer is to target devices drawing over 5W on standby, such as set-top boxes or desktop PCs, to see real savings of £10–15 per device.
- Forgetting the smart plug’s own power draw Many people do not account for the 0.5–1W the smart plug uses to stay connected to Wi-Fi and respond to commands. This can cancel out savings from low-power items. The right answer is to measure the device’s standby draw with a plug-in meter and only use a smart plug if the device uses at least 2W more than the plug itself.
- Leaving devices on standby during the day Homeowners often set schedules to switch off overnight but forget about daytime hours when nobody is home. This misses half the potential savings. The right answer is to programme smart plugs for both overnight and working-day hours, cutting standby time by 16 hours a day and doubling annual savings to £15–20 per device.
Quick reference
- A Sky Q box uses 28W on standby, costing roughly £20 a year at 27p/kWh. That makes it one of the best targets for a smart plug.
- The Energy Saving Trust estimates standby power waste costs UK households £55 annually, and smart plugs can recover 15–20% of that per device.
- ECO4 and the Great British Insulation Scheme do not cover smart plugs, but the 0% VAT on energy-saving materials applies until March 2027.
- A £10 smart plug on a high-standby device pays for itself in under a year and saves £10–15 annually thereafter.
- Never use a smart plug on a device drawing under 0.5W on standby, as the plug’s own 0.5–1W draw will negate any savings.
Frequently Asked Questions
UK appliances like TVs and set-top boxes use 1–10 watts on standby. The Energy Saving Trust reports standby power costs the average household £55 a year.
Yes, a smart plug uses about 0.5–1 watt of standby power. Ofgem data shows you need to switch off a device drawing more than that to see net savings.
Schedule your smart plug to cut power to high-standby devices like satellite boxes or desktop PCs overnight. The Energy Saving Trust recommends targeting items over 10W standby for maximum savings.
