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Smart meters explained

What is a smart meter?

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What is a smart meter?

Find out more about smart meters - from what smart meters do, to whether a smart meter will save you money.

Smart meters give both you and your energy provider accurate and regular updates on how much electricity and gas you use.

Like traditional gas and electricity meters, smart meters measure your energy use. The main difference is that smart meters automatically send your usage information through mobile networks to your supplier.

Your smart meter will come with an in-home display (IHD), which will show you how much energy you use in real time. Like energy monitors, smart meters should help you to better control your energy use.

Here, we explain exactly what smart meters are, whether getting a smart meter installed will save you money and how smart meters differ from energy monitors.

Smart meters – what can they do?

Smart meters will replace your existing gas and electricity meters. They will send all the information about how much gas and electricity you're using directly to your energy supplier using wireless networks, similar to mobile phone networks. This means no more manual meter readings and the end of estimated bills.

Smart meters also offer additional possibilities for the future – such as improved ‘time-of-day tariffs’ offering cheaper rates at off-peak times to smooth out national energy usage through the day.

Between 2016 and 2020, energy companies will replace every meter in Great Britain. That's 53m meters in total, at a cost of £11bn. 

When you have a smart meter installed, you'll get a smart energy meter, a smart gas meter and also be offered an in-home display. These elements will talk to each other wirelessly. Your electricity meter will tell you how much energy you're using in real time. But your gas meter will be asleep for most of the time, waking up every half an hour to give a reading. 

How are smart meters different from energy monitors?

Smart meters will actually replace your current meter and automatically transmit regular meter readings to your supplier. Whereas an energy monitor will simply clip on to your power cable and give you a good estimate of the amount of electricity you are currently using.

A smart meter will be provided by and installed by your energy provider. You can buy an energy monitor from a shop and install it yourself. The video below shows you what the differences are between a smart meter, an in-home display and an energy monitor.

Smart meter video guide: differences between a smart meter and energy monitor

Energy monitors can cost from around £20 to £100. We’ve found that some are accurate and easy to use - so they will help you to reduce your energy bills. But we've also discovered models that are fiddly to install and use. 

See our energy monitors explained guide to make sure you don't waste your money on the wrong model. 

Will smart meters save me money?

A smart meter will mean more accurate bills - and remove the costs of meter readings, which are currently added to your bills. 

The government estimates that the smart meter roll-out will save energy companies about £8bn over 18 years through operational savings such as meter readings. Energy providers should then, in principle, pass on these savings to consumers.

Consumers are predicted to also collectively save £4.3bn through energy savings at home. However, smart meters will only save you money if you use and act on the information provided by your in-home display to reduce your energy consumption.

According to government estimations, smart meters will help to reduce electricity usage by around 2.8% and gas use by around 2% on average. This could save £15 on electricity bills and £12 on gas bills a year.  

Which? can help you make savings now - take a look at our expert advice on cutting your energy bills and using less electricity

Are smart meters free?

While having a smart meter installed is free, you'll incur the cost indirectly through your bills. It's estimated that the smart meter roll-out will cost every home about £215.

At the moment the roll-out is being led by the energy companies, with no checks in place to make sure that costs don't spiral. Energy suppliers will make cost savings via the roll-out, so we want suppliers to pass on these savings in full to their customers.

Which? wants the cost of the roll-out to be kept in check and we're campaigning for cost control and scrutiny of the smart meter roll-out. 

How can I get a smart meter?

Some energy companies - including British Gas, EDF Energy, Eon, First Utility, Ovo, Utilita and SSE - have already started providing their own smart meters to customers. Other smaller suppliers will soon be obliged to begin installing smart meters too, as the government has set deadlines for when suppliers must complete their roll-outs.

Find out what you need to know about the smart meter roll-out.

How will my smart meter be installed?

Your energy company will get in touch to arrange a suitable time and date for your smart meter to be installed. Or you can contact it to arrange an appointment. The installation itself will be carried out by a trained installer from the energy company. You'll need to be at home during the installation appointment. 

British Gas estimates that a typical smart meter installation will take around 1.5 hours – but it will differ from property to property, and depend on where your current meters are located.

As part of the installation, your energy company may offer to carry out an energy-efficiency inspection of your home and give you energy-efficiency advice. However, no sales transactions can take place during a domestic installation visit.

Take a look at our video of a smart meter being installed to see what's involved.

How big is a smart meter?

You'll get two smart meters – one for gas and one for electricity (or just an electricity one if you haven't got gas). The smart gas meters are about the same size as current gas meters, while you may find that your electricity smart meter is slightly bigger than the old-style meter you have now. 

Your gas smart meter will be battery-powered and only wake every half an hour to give you a reading. The electricity smart meter will be plugged into the mains and give moment-to-moment readings. The gas meter 'talks' to the electricity meter, which sends the information to your energy provider.

Are smart meters safe?

Some people have complained about the impact of smart meters on their health, in particular those suffering from electromagnetic sensitivity or electromagnetic hypersensitivity. 

The smart meter information campaign for consumers, Smart Energy GB, told us: 'Public Health England has tested the equipment that comes closest to the specification set out for smart meters. It says that the evidence to date suggests exposure to the radio waves that the equipment produces doesn’t pose a risk to health. There will be further research on the actual equipment that will be installed when it becomes available.'

How often will my smart meter need to be replaced?

Smart meters will need to be replaced around every 10 years – which is more often than current gas and electricity meters. Again, your energy company will let you know when your smart meter is due to be replaced, and arrange a time and date for this to happen.

Will having a smart meter affect me switching energy suppliers?

Long term, it's hoped that smart meters will make it quicker to switch energy suppliers – in theory, a smart meter can be instructed to send information about your energy usage to a new energy company instantaneously.

In the short term, smart meters may actually be a barrier to switching. Those getting a smart meter installed before second generation (SMETS2) meters are available (expected to be late 2017, or early 2018) may have to have their meter switched to 'dumb' mode if they wanted to switch supplier, as their smart meter may not be compatible with their new supplier. If this happens, you'd have to have manual readings taken again. 

Before 2020, any first generation meters already installed will need to be upgraded remotely and should be compatible with all energy suppliers.

Fed up with poor customer service or of paying too much for energy? Then switch. Use our independent switching service to compare gas and electricity suppliers and find a cheaper deal.