How Wi-Fi Smart Plugs Can Save Money and Automate Your Home

One of the cheapest smart home devices you can buy is also one of the most useful — here's what a smart plug actually does and where it earns its keep.

What they do

A Wi-Fi smart plug sits between a normal power outlet and whatever you plug into it, giving you app-based control over that appliance from anywhere — turn it on or off remotely, set schedules, and on many models, track how much power the connected device is actually using.

Where they actually save money and hassle

• Killing standby power: TVs, consoles, and entertainment setups draw power even switched "off" at the wall. Scheduling a smart plug to fully cut power overnight removes that phantom draw automatically.
• Scheduling lamps and lighting: useful for the classic "look occupied while away" case, or simply not having to remember to turn things off before bed.
• Pre-heating or pre-cooling: turn a heater on shortly before you get home via the app, rather than either leaving it running all day or arriving to a cold house.
• Spotting power-hungry appliances: plugging an older heater, dehumidifier, or appliance into an energy-monitoring smart plug for a week is a quick way to actually see what it costs to run, rather than guessing.

Safety

What to look for when buying

• Energy monitoring: not all smart plugs report power usage — if tracking cost is the main reason you want one, confirm the model actually supports it before buying.
• Local vs cloud control: some brands require their own app and cloud account to function at all; others support local network control or work directly with Google Home / Apple Home / Alexa without a separate account.
• NZ plug standard and rating: confirm it's rated for NZ's 230V/240V supply and comes in the correct AS/NZS plug type — grey-import listings sometimes don't.