What does a power meter do?
Energy meters (sometimes called power meters) measure energy use and calculate the hourly, quarterly and annual running costs of household appliances. Some also estimate the greenhouse gas emissions produced by different appliances. They're generally easy to use: you simply plug your appliance into the meter, and it'll present all the necessary data on an LCD screen. You can then identify power-hungry gadgets, and work out an effective energy saving scheme.
The good news is that when we tested power meters in the past, we found that you don't need to spend top dollar to get a good one – most of the cheaper models will do the job. However, they're not to be confused with in-home displays (IHDs) or smart switches, even though they're quite similar.
Meters, in-home displays or smart plugs?
In-home displays, or IHDs, are a simplified version of your home's energy meter. Basic models indicate whether you're in a low, medium or high price period, so you can work out the most cost-effective time to use appliances that don't need to run all day. Advanced units can indicate the amount of energy being used by your home at any given time and the approximate cost, usage history, and even predicted price hikes.
These are based on factors such as weather, e.g. energy costs increase on cold days because everyone's using a heater. Features like this require an internet connection, which is why some IHDs are known as 'smart meters'.
While IHDs are a handy way to get a snapshot of your home, most can't measure individual devices. We suggest using one in conjunction with energy meters or even smart switches, such as Belkin's WeMo range. These add simple automation functions to items around your home, such as lamps, televisions and kitchen appliances, which you can control with your smartphone.
Some switches include energy-monitoring features that sync to an app on your smartphone. These typically let you track multiple devices at once, which is much more convenient compared to using a dedicated power meter per device. However, the features and feedback in these apps isn't quite as in-depth.
What to look for
This shows you the estimated volume of greenhouse gas produced to generate the energy consumed by the appliance.
Customisable measurement periods
The ability to set your meter to only record data at certain times (such as expensive periods), so you don't need to sift through potentially unnecessary information, such as power consumption while you're asleep.
Energy usage history
A handy feature that helps you track data consumption over time to develop useful energy saving techniques.
Look for a power meter that displays readings in kilowatt hours (kWh) as this is what you see when you get your energy bill.
Multiple appliance input
It's a good idea to get a meter that can monitor several appliances at once – that way you can get an idea of your energy use much more quickly.
Multiple stored charged rates
This feature lets you input multiple rates (peak, shoulder and off-peak, for example) and calculate your appliance's energy cost more precisely.
Power outages can affect the data stored in the power meter or wipe it completely. Non-volatile memory prevents this and lets your meter resume as normal once power comes back on.
This lets you take readings without having to access the main socket unit.
Top tips for saving energy
1. Know your different pricing tariffs and take advantage of off-peak pricing for appliances like washing machines, dryers and dishwashers. If you have a smart meter, the tariffs may vary depending on the time of day.
2. Turn off appliances at the power point, as even standby mode still uses energy in some appliances.
3. Check the energy rating label if you're buying a new big ticket item like a TV or fridge. Buying an energy-efficient appliance will keep your electricity bill down for years to come.
4. Switch to CFL (compact fluorescent lamps) or LED (light emitting diodes) lighting. They're more expensive in the short term, but they use less energy and last longer.
5. Consider the appliances you have and how you can save energy. If you have an old second fridge, for example, you could save up to $250 a year by giving it the flick.