Over 70% of meters in Great Britain are now smart meters - around 40 million devices sending automatic readings to suppliers across the country. If you've had one installed recently (or have had one for a while but aren't really using it), you might be wondering what you're actually supposed to do with it.
Here's what a smart meter can and can't do for you, and how to get more value from the data it's generating.
A smart meter records your electricity usage in near-real time and your gas usage in half-hourly intervals. It sends those readings automatically to your supplier - which means accurate billing without meter reading appointments, and no more estimated bills based on what you used two years ago.
That's genuinely useful. Estimated billing has been one of the most persistent sources of billing errors in the energy market: if your supplier underestimates your usage, you can end up with a large true-up bill months later. Smart meters eliminate that.
But automatic readings are just the baseline. The more interesting capability is what you can do with the data yourself.
When your smart meter was installed, you were probably given an in-home display (IHD) - a small screen that shows your live energy consumption in pounds and pence. It updates every few seconds for electricity, making it the most immediate way to see your usage in real time.
IHDs are useful for spotting obvious wastage: leaving a device on standby that you thought was off, identifying which appliances have the highest draw, seeing how your usage pattern changes across the day. Surveys consistently find that households with smart meters reduce their energy consumption after installation - in part because seeing usage in real time creates an immediate feedback loop that estimates and quarterly bills simply can't.
But IHDs have real limitations. They typically don't store historical data in an accessible way, don't generate alerts, and don't help you understand whether your supplier is giving you the best available rate. For that, you need to go further.
Most large suppliers now offer apps that let you view your historical smart meter data - usage by day, week, and month, sometimes by half-hour slot. This is genuinely more useful than the IHD for spotting patterns: when is your household using most energy? How does a cold week compare to a mild one? Is your overnight consumption higher than expected (which can indicate a faulty appliance or a device left on)?
The limitation of supplier apps is structural: they only show you your usage data. They don't tell you whether you're on the right tariff, whether your rate is competitive, or what you'd save by switching. That information is in their interest not to surface prominently - they want you to stay.
Your smart meter tells you how much energy you're using. It doesn't tell you whether you're paying the right amount for it.
Those are two different things. A household that's efficiently managing its consumption but sitting on a standard variable tariff paying cap-level rates could still be overpaying by £200–£400 a year relative to the cheapest available fixed deal. The smart meter gives you no visibility of that.
This is where the data your smart meter generates becomes genuinely powerful - but only if it's combined with tariff comparison. The right question isn't just "how much am I using?" but "given what I'm using, am I on the best available deal?"
Smart meters enable a category of tariff that traditional meters can't support: time-of-use (TOU) tariffs, which charge different unit rates depending on when you use electricity.
The most established version in the UK is the Octopus Agile tariff, which changes price every 30 minutes based on wholesale electricity prices. At off-peak times (often overnight), rates can fall dramatically - sometimes even going negative, meaning you're paid to use electricity. At peak times (typically 4pm–7pm), rates can spike.
For households that can shift flexible loads - charging an electric vehicle overnight, running a dishwasher or washing machine at midnight - TOU tariffs can represent significant savings. But they require a smart meter with half-hourly data sharing enabled, and they require some willingness to adapt behaviour around the tariff schedule.
Other TOU products are simpler: flat cheaper overnight rates (similar to the old Economy 7 model but more flexible), weekend pricing, or export tariffs for households with solar panels.
If you have a smart meter and an electric vehicle or solar panels, TOU tariffs are worth investigating seriously.
A few practical steps:
Enable half-hourly data sharing with third parties. By default, some suppliers only share meter data at daily or monthly granularity. Switching to half-hourly data sharing (usually controllable in your supplier's app or account settings) unlocks access to more detailed analysis tools and better tariff comparisons.
Check your historical usage before comparing tariffs. The single biggest improvement you can make to a tariff comparison is to use your actual annual consumption rather than the "typical household" estimate. Your smart meter data gives you this exactly - look for kWh figures in your supplier app or on your bill.
Use your actual consumption to compare. When you know your real annual electricity and gas consumption, tariff comparison becomes far more accurate. A tariff with a lower unit rate but higher standing charge might be cheaper for a high-consumption household but more expensive for a low-consumption one. The "typical household" estimate hides this.
Set a reminder to compare tariffs when your fixed deal expires. If you switch to a fixed deal (which is often the cheapest option), note the end date and set a reminder about 49 days before it expires - that's when you can switch without exit fees. Letting a fixed deal roll onto SVT without comparing alternatives is one of the most common and costly mistakes households make.
EnergyScan connects directly to your smart meter data via the national secure infrastructure (with your consent) to give you a live dashboard of your energy usage, accurate tariff comparison based on your real consumption, and ongoing alerts when a better deal becomes available.
It's designed specifically for households that have a smart meter and want to do more with the data it generates - not just see usage, but act on it.
Connect your smart meter and see your dashboard →
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EnergyScan is an independent energy monitoring service. We earn a disclosed commission of £20 per fuel when you switch through us. We never earn more by recommending a more expensive tariff.
Last updated: 2026-03-07.
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