A Simple Guide to How Smart Meters Work
Smart meters are gradually replacing traditional gas and electricity meters across Great Britain.
Like traditional meters, they record the energy you use. However, smart meters can also communicate meter readings automatically, which means you should not normally need to submit readings yourself when everything is working correctly.
They can also provide more detailed information about your energy use and make new types of energy tariff possible.
However, a smart meter does not automatically reduce your energy bill.
Instead, it provides better information and enables services that may help you manage your energy differently.
What Is a Smart Meter?
A smart meter measures the gas or electricity used by your home.
Unlike a traditional meter, it can send readings through the smart-meter communications system. Therefore, your supplier can normally receive readings without somebody visiting the property or you submitting them manually.
If you have both gas and electricity, you will normally have a separate smart meter for each fuel.
The meters communicate as part of the wider smart-meter system.
What Is an In-Home Display?
When smart meters are installed, households are normally offered an in-home display, often shortened to IHD.
This is the small screen that you may keep in your kitchen, hallway or living room.
Importantly:
The in-home display is not your smart meter.
Your actual meters remain where the gas and electricity meters are installed.
Instead, the IHD receives information from the smart-meter system and presents it in a convenient form.
Depending on the model and setup, it may show:
- Current electricity use
- Recent energy consumption
- Estimated energy costs
- Gas and electricity information
- Daily, weekly or monthly usage
Therefore, the display can make your energy consumption much easier to see.
Using a Smart Meter With a Phone App
You may also be able to view your smart-meter information through an app on your smartphone or tablet.
Many energy suppliers provide apps that allow customers to see information collected from their smart meters.
Depending on your supplier, meter and account settings, the app may show:
- Daily energy use
- Weekly and monthly consumption
- Gas and electricity use in kWh
- Estimated energy costs
- Previous meter readings
- Usage graphs and trends
- Account balance
- Bills and payments
Therefore, you do not necessarily have to rely on the in-home display to understand your energy use.
In fact, an app can sometimes make it easier to see longer-term patterns.
For example, you might compare your electricity use this week with last week. Similarly, you may be able to see how your gas consumption changes as the weather becomes colder.
Apps Can Make Smart Tariffs Easier to Use
Phone apps can become particularly useful if you are on a smart or time-of-use tariff.
Depending on the tariff, an app may help you see:
- When electricity is cheaper
- When prices are higher
- Your consumption during different periods
- EV charging information
- How much electricity you have used during off-peak periods
Some tariffs and technologies can also work with apps to help schedule energy use during cheaper periods.
Therefore, the combination of a smart meter, suitable tariff and useful app can give you greater control over when you use electricity.
However, features vary considerably between suppliers and tariffs.
Learn about choosing the right tariff →
Your Supplier’s App Is Not the Only Option
Depending on your smart meter and the permissions you provide, you may also be able to use compatible third-party apps and energy services to view or analyse your smart-meter data.
These services may present your consumption differently or provide additional tools for understanding your energy use.
However, before giving a third-party service access to your energy data, check:
- Who operates the service
- What information it will access
- How your data will be used
- What permissions you are granting
- How you can withdraw access
Therefore, don’t give an app access to your smart-meter information simply because it promises to save you money.
Understand what you are agreeing to first.
The Meter, Display and App Have Different Jobs
It may help to think of the three separately.
Smart meter
Measures your energy consumption and communicates meter data.
In-home display
Shows energy information conveniently inside your home, including near-real-time information where available.
Phone app
Can provide convenient access to your energy information, account and longer-term consumption patterns, depending on the service.
You do not necessarily need to use all three.
For example, someone who prefers using their phone may rarely look at the in-home display. Meanwhile, another person may prefer having the IHD in the kitchen without needing to open an app.
The important thing is to use whichever tools help you understand your energy consumption without making it complicated.
How Does a Smart Meter Send Readings?
Smart meters do not normally use your home broadband or Wi-Fi to send readings to your supplier.
Instead, they use a dedicated smart-meter communications system.
Therefore, you do not need an internet connection simply for the smart meter to send readings.
However, communication methods and performance can vary depending on the equipment and location.
The important point is that the metering system communicates independently of your normal home internet connection.
Does a Smart Meter Send Readings Constantly?
Not necessarily.
Your smart meter can collect information at intervals and send data through the smart-meter system according to the arrangements applying to your account.
Depending on your choices and circumstances, readings may be recorded and shared at different frequencies.
Therefore, having a smart meter does not mean your supplier is continuously watching every appliance you use.
The meter records the amount of energy passing through it. It does not identify whether that electricity was used by your television, kettle, washing machine or another individual appliance.
Do Smart Meters Make Bills More Accurate?
Smart meters can reduce the need for estimated readings because actual readings can normally be sent automatically.
As a result, your supplier should have more regular information about the amount of energy you have used.
However, a smart meter does not guarantee that every bill will always be correct.
Billing problems can still occur, while communication problems may occasionally mean that your supplier does not receive an automatic reading.
Therefore, it is still worth checking your energy bills.
Learn how to understand your energy bill →
Do I Still Need to Read My Smart Meter?
Usually, you should not need to submit regular manual readings if your smart meter is communicating correctly.
However, knowing how to read it is still useful.
For example, you may need a manual reading if:
- Your supplier asks for one
- Automatic readings are not being received
- You are checking a bill
- You are moving home
- You are investigating unusual energy consumption
Different smart-meter models have different displays and buttons. Therefore, the exact method for obtaining a reading can vary.
Learn how to read your energy meter →
Can a Smart Meter Save You Money?
A smart meter does not reduce energy consumption by itself.
Installing one does not make your boiler more efficient, improve your insulation or reduce the amount of electricity used by an appliance.
However, the information it provides may help you make different decisions.
For example, you might notice:
- Higher electricity use at particular times
- Unexpected overnight consumption
- How much electricity your household uses when little is happening
- How consumption changes when certain equipment is being used
- Differences between one day and another
As a result, you may identify energy use that you want to reduce.
But the decision to change something remains yours.
Don’t Obsess Over the In-Home Display
An in-home display can be useful, but it should be treated as a tool rather than a scoreboard.
For example, switching on a kettle can make current electricity consumption jump sharply. However, that does not necessarily mean the kettle is expensive to use overall.
A kettle has a relatively high power rating, but it normally operates for only a short time.
Therefore, look at energy consumption over time, rather than becoming concerned whenever the display suddenly shows a high number.
The same principle applies to other high-powered appliances that operate for relatively short periods.
Understand Energy and Cost Displays
An IHD or phone app may allow you to view information in different ways.
For example, you may be able to see:
- Energy in kWh
- Estimated cost in pounds and pence
- Current electricity demand
- Consumption over a particular period
These figures answer different questions.
kWh tells you how much energy has been consumed.
Meanwhile, £ and pence gives you an indication of cost based on the tariff information available to the system.
Therefore, when investigating your actual energy consumption, kWh is particularly useful.
Why Might the Cost on the Display Look Wrong?
Sometimes, the estimated cost shown on an in-home display or app may not appear to match your bill.
There can be several reasons for this.
For example, tariff information may not be fully up to date, while the display or app may present information differently from your supplier’s bill.
Your bill may also include charges or account information that the simple display figure does not represent in the same way.
Therefore, use these tools primarily as a helpful guide to consumption rather than treating them as a replacement for your energy bill.
What Are Smart Tariffs?
One important benefit of smart meters is that they can support tariffs that depend on more detailed information about when electricity is consumed.
These are often described as smart tariffs or time-of-use tariffs.
For example, electricity might be:
- Cheaper overnight
- More expensive during peak periods
- Particularly cheap during certain charging periods
- Priced differently at different times
This can be useful if you can move substantial electricity consumption into cheaper periods.
For example, you might be able to change when you:
- Charge an electric vehicle
- Charge a home battery
- Heat water
- Use certain appliances
However, a smart tariff is not automatically cheaper.
Your savings depend on the tariff and when you actually use electricity.
Learn about choosing the right tariff →
Smart Meters and Electric Vehicles
Smart meters can become particularly useful for households with electric vehicles.
Some EV tariffs offer cheaper electricity during specified periods, often designed around overnight charging.
Therefore, a household may be able to charge its vehicle when electricity is cheaper rather than using electricity during more expensive periods.
However, always check the complete tariff.
A cheap EV charging rate does not automatically mean every other rate on the tariff is competitive.
Smart Meters and Home Batteries
A home battery can also work with certain time-of-use strategies.
For example, depending on the tariff and equipment, a battery might charge when electricity is cheaper and provide energy to the home later.
As a result, this can reduce the amount of electricity bought during more expensive periods.
However, batteries involve significant upfront costs and are not automatically cost-effective for every household.
Therefore, tariff savings should be considered alongside the cost, performance and expected life of the battery system.
What Happens If the Smart Meter Loses Communication?
Sometimes, a smart meter may stop communicating properly.
If this happens, the meter can generally continue measuring the energy you use. However, your supplier may stop receiving automatic readings.
As a result, you may temporarily need to provide manual readings.
A communication problem does not normally mean that your gas or electricity supply will simply stop.
If you think your smart meter has stopped sending readings, contact your energy supplier.
What If the In-Home Display Stops Working?
A problem with the in-home display does not necessarily mean there is a problem with the smart meter itself.
Remember:
Smart meter = measures your energy
In-home display = shows you information
Therefore, your smart meter may still be recording and communicating readings even if the IHD is not displaying information correctly.
If the display stops working, check the manufacturer’s or supplier’s instructions and contact your supplier if necessary.
You may also still be able to view useful information through your supplier’s app or online account.
What If the Phone App Stops Showing Data?
Again, this does not necessarily mean your smart meter has stopped working.
The problem could relate to the app, your account or the way information is being provided to the service.
First, check whether your latest bills are still using smart-meter readings.
You can also check the meter itself if necessary.
If automatic readings appear to have stopped reaching your supplier, contact them for help.
Will a Smart Meter Work Everywhere?
Smart-meter communications can be more difficult in some properties or locations.
For example, challenges may arise because of:
- The location of the meters
- Building construction
- Distance between gas and electricity equipment
- Communications coverage
- The particular installation
Therefore, not every property will have exactly the same experience.
If a suitable smart-meter installation cannot be completed, your supplier should explain the available options.
What Happens If I Change Supplier?
Modern smart meters are designed to operate within the national smart-meter system, which is intended to allow smart functionality to continue when customers change supplier.
However, individual circumstances and equipment can vary.
Therefore, after switching, check that:
- Automatic readings are being received
- Your online account or app shows sensible information
- Your bills use appropriate meter readings
- Your in-home display continues to show useful information
If something stops working correctly after a switch, contact your new supplier.
What About Older Smart Meters?
You may hear the terms SMETS1 and SMETS2.
These refer to different generations or technical specifications of smart-meter equipment.
Some earlier smart meters could lose certain smart functions when customers changed supplier. However, many older meters have since been migrated into the national smart-meter communications system.
For most householders, the technical distinction is less important than the practical question:
Is my meter communicating correctly with my current supplier?
If you are unsure, check your bills or ask your supplier.
Are Smart Meters Safe?
Smart meters must meet relevant technical and safety requirements.
They use radio communications to exchange information, which can sometimes lead to concerns about electromagnetic fields.
However, smart meters are designed to operate within applicable exposure limits.
As with other energy equipment, you should not open, alter or interfere with the meter yourself.
If you believe the meter is damaged or unsafe, contact your energy supplier.
What About Privacy?
Smart meters collect information about how much energy is used and when it is used.
Therefore, it is reasonable to ask how that information is handled.
Rules govern access to smart-meter consumption data, and different arrangements can apply depending on how detailed the information is and why it is being used.
Your supplier should explain its privacy arrangements and your choices concerning energy-use data.
Importantly, a smart meter measures energy consumption.
It does not provide your supplier with a camera or microphone inside your home, nor does it directly tell them which individual appliance you are using.
If you choose to give a third-party app access to your energy data, however, check its privacy terms and permissions separately.
Do You Have to Have a Smart Meter?
Smart meters are part of the move towards a more flexible energy system, and suppliers are required to take steps to install them across eligible homes and businesses.
However, whether a particular installation can or must proceed can depend on the circumstances.
If you have concerns about an offered installation, ask your supplier what is being proposed and what options apply to you.
That is better than relying on general claims that smart meters are either always compulsory or always optional.
Should You Get a Smart Meter?
For many households, smart meters offer useful benefits.
These can include:
- Automatic meter readings
- Less reliance on estimated readings
- Better information about energy consumption
- Access to certain smart and time-of-use tariffs
- Easier monitoring through an in-home display
- Access to energy information through compatible phone apps
- Greater possibilities for EV charging and home-energy technologies
However, the meter itself does not guarantee lower bills.
Instead, the real benefit comes from better information, easier metering and access to services that traditional meters cannot always provide.
If Something Goes Wrong
If you have a problem with your smart meter, your first contact will normally be your energy supplier.
For example, contact your supplier if:
- The meter appears faulty
- Automatic readings have stopped
- Your account repeatedly shows estimated readings
- You cannot obtain a meter reading
- Your in-home display has persistent problems
- You have questions about your smart-meter data
However, responsibility changes once you move away from the meter itself.
For example, your electricity network operator is responsible for network equipment, while the property owner is normally responsible for internal electrical wiring.
Learn who is responsible for your energy supply →
In Short
A smart meter records your gas or electricity use and can communicate readings automatically.
Meanwhile, an in-home display provides a convenient way to see energy information inside your home, while a phone app may allow you to explore your consumption, account and longer-term patterns wherever you have access to the service.
Smart meters can:
- Reduce reliance on estimated readings
- Remove much of the need for manual readings
- Help you understand consumption
- Support smart and time-of-use tariffs
- Provide useful information through displays and apps
- Make more flexible energy use possible
However, they do not automatically reduce your bills.
Instead, think of a smart meter as providing better information and greater possibilities.
The meter measures your energy.
The in-home display makes that information easy to see around the home.
The app can make it easier to understand patterns over time and, depending on the tariff, help you manage when you use energy.
Use whichever tools are useful to you.
Then use the information they provide to make better-informed decisions about your energy.
Energility
Understand More. Spend Less. Live Better.