What is a smart plug? How they save energy & reduce emissions.

Hannah 14 Oct 2022

A smart plug is a device that fits in between the power socket in your wall and an appliance. They are similar in appearance to power adapters you may have used when traveling. The reason they get the ‘smart’ moniker is because these plugs allow you to control the appliance they’re plugged into remotely, enabling them to function in more environmentally efficient and useful ways.

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How do smart plugs work?

The majority of smart plugs work by connecting to wifi, and then are controlled by an app or through a smart home hub, like Amazon Alexa, Google Home, or Apple Homekit. This means you’ll be able to remotely control the power going into your connected appliances, and set up automated actions. Every appliance that you have connected to a smart plug can then be visible and controllable from one place.

What are the benefits of using a smart plug?

  1. Reduce your carbon footprint

    Using smart plugs can allow you to minimise the amount of electricity your household uses unnecessarily. When your devices are turned off but still plugged in, they continue to draw electricity, a concept known as standby or phantom power. One solution is to ensure you always unplug your appliances when they are not in use. However, smart plugs are a significantly simpler solution because you can use an app to easily turn off an appliance when you aren’t using it. You can even do it from outside your home.

    Additionally, you can set up automation and schedules. For example, if you and your partner leave the house for work every day at 8 am, you can schedule your connected appliances to stop drawing electricity until you return in the evening. This allows you to reduce your carbon footprint by only using electricity when you need it for operating your appliances.

  2. Measure the energy consumed by your appliances

    Some smart plugs can give you greater insight into the energy consumption of appliances in your home when they are plugged in. This is an important step in reducing your household emissions because it gives you a precise method to identify which appliances are actually consuming a lot of electricity. Without data-driven insight into how much electricity your devices are drawing, you may just be guessing. Knowing which devices are the most energy intensive can help you make more conscious and informed decisions, especially if you use the Zerofy app’s carbon intensity feature, which tells you when your grid-electricity is greenest.

  3. Save money on energy bills

    Phantom power isn’t just a contributor to your household emissions—it also can impact your budget. A 2022 study from British Gas found UK households spend approximately £147 per year on electricity from phantom power [1]. Using smart plugs means you can minimise the cost of electricity from the slow drain of appliances you aren’t using. At a time when the cost of household energy is a real concern for most, a device that allows for more mindful spending on electricity can be extremely useful.

  4. Make your life simpler while doing both the above

    Apart from the benefits of reducing household emissions and saving money on energy bills, smart plugs can make your life more convenient. Here’s a few examples:

    • Schedule your Christmas lights to turn on for a few hours in the evening and then turn off by themselves
    • Create the illusion you are home by turning a lamp on while on holiday
    • Turn on your slow cooker from the office
    • Easily turn off appliances you left on by accident, like a clothes dryer, without having to return home
    • Turn on your electric kettle while lying in bed
    • Get alerts on your phone when an appliance finishes its program (e.g. washer or dryer)
    • Measure energy use and identify biggest electricity consumers in your household

smart plug in wall

What is the best smart plug?

The best smart plug is the one that meets your needs and budget, works in your country, and integrates with any home technologies you already use, like Zerofy, Amazon Alexa, Google Home, or similar. To help select the best smart plug for you, we’ve compiled a smartplug comparison chart.

When putting together our comparison chart, we evaluated based on the below criteria:

  • Can the plug work with just wifi, without the need to set up a dedicated hub device first? Our preference is that just working with wifi is better.
  • Can you access the smart plug remotely by simply using a cloud app?
  • Does the smart plug measure energy consumption?
  • Which smart home platforms does the smart plug integrate with?

Based on this criteria, the two smart plugs we recommend are the MyStrom Switch, and the Shelly Plug S. Both of these smart plugs we found to be very versatile in terms of integrating with smart home platforms. They also both measure energy consumption, and have a good max power limit.


[1] BBC: Energy supplier counts cost of devices on standby