Best home energy monitors UK (2026): smart plugs, clamp monitors and the free display you may already own
An energy monitor puts a number on electricity you would otherwise only meet on a bill: what the house is drawing right now, or what one freezer, dehumidifier or games console uses. There are two ways to get that number without touching the meter: a smart plug with monitoring, which meters one appliance at a time, and a clamp monitor, which clips a sensor round the incoming supply cable and sends a whole-home reading to a screen. We compare both using the makers' own pages and a second independent listing; we have not fitted or measured any of them ourselves, and none saves anything until you change something.
By Tom Calder · Updated 21 October 2026 · 4 products, all price-tracked
Our picks by type
Photo: AmazonTapo P110
Finding out what one appliance, such as a freezer, dehumidifier or desktop PC, draws and costs to run.
as of 21 Oct 2026, 10:37 BST · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Photo: AmazonEfergy E-Max 1 CT
A whole-home reading on a screen you can carry from room to room, with nothing to set up on a phone.
as of 21 Oct 2026, 10:37 BST · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.All 4 compared
| Monitor | Type | Needs | App | Power | Price |
|---|---|---|---|---|---|
Smart plug (one appliance) · 2.4GHz Wi-Fi, phone, 13A socket · Tapo app · Mains, 220-240V Finding out what one appliance, such as a freezer, dehumidifier or desktop PC, draws and costs to run. | Smart plug (one appliance) | 2.4GHz Wi-Fi, phone, 13A socket | Tapo app | Mains, 220-240V | £9 at Amazon as of 21 Oct 2026, 10:37 BST · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A plug-in monitor that needs no electrician and no access to the meter, which makes it the simplest way to put a number on a single appliance. Readings show in the Tapo app, which can also run schedules and timers. It tells you nothing about the rest of the house, and measuring a device saves nothing until you change how you use it. Best for Finding out what one appliance, such as a freezer, dehumidifier or desktop PC, draws and costs to run. Good
Worth knowing
Who shouldn't buy it: You want a whole-house figure on a screen: if you have a smart meter, ask your supplier for the free in-home display that comes with it. Appliances rated above the plug's limit also rule it out. | |||||
 Smart plug x4 (one appliance each) · 2.4GHz Wi-Fi; Bluetooth for setup · Tapo app or a Matter app · Mains, 100-240V Checking several appliances at once, or leaving a plug on each always-on device for a few weeks. | Smart plug x4 (one appliance each) | 2.4GHz Wi-Fi; Bluetooth for setup | Tapo app or a Matter app | Mains, 100-240V | £38.99 at Amazon as of 21 Oct 2026, 10:37 BST · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched Four plug-in monitors in one box, with Matter support for people who already run Apple Home, Alexa, Google or SmartThings, all listed by TP-Link. Spread round the house they show the biggest single draws, but they still add up to a partial picture rather than the whole-house total. The numbers only help once you act on them. Best for Checking several appliances at once, or leaving a plug on each always-on device for a few weeks. Good
Worth knowing
Who shouldn't buy it: You only want to check one or two appliances, where a single plug does the job, or you want the whole-house figure: with a smart meter, your supplier's free in-home display gives that. | |||||
Clamp, transmitter and display · One clamp round the supply cable · No app stated; USB data download · USB 5V or alkaline batteries A whole-home reading on a screen you can carry from room to room, with nothing to set up on a phone. | Clamp, transmitter and display | One clamp round the supply cable | No app stated; USB data download | USB 5V or alkaline batteries | £99.95 at Amazon as of 21 Oct 2026, 10:37 BST · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched A traditional clamp monitor: a sensor round the incoming supply cable, a radio transmitter and a 7.9in display. Efergy states a 10-second update and up to 70m of range in open space. There is no app; history comes off the display by USB. It shows where the power goes, but the saving depends on what you change. Best for A whole-home reading on a screen you can carry from room to room, with nothing to set up on a phone. Good
Worth knowing
Who shouldn't buy it: You have a smart meter: ask your supplier for the free in-home display that comes with it before buying one. If the supply cables are boxed in, hard to reach or look damaged, have an electrician fit the clamp rather than forcing it. | |||||
 Clamp, transmitter and display · Three clamps, one per phase · No app stated; USB data download · USB 5V or alkaline batteries Homes or small premises on a three-phase supply that want one whole-site reading on a screen. | Clamp, transmitter and display | Three clamps, one per phase | No app stated; USB data download | USB 5V or alkaline batteries | £139.95 at Amazon as of 21 Oct 2026, 10:37 BST · DetailsProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.In stockCheck price → |
Our verdictOur verdictResearched The three-sensor version of the E-Max, with larger 19mm XL clamps for thicker cables, sold by Efergy as its three-phase option. It keeps the same 7.9in display and USB download, and has no app. Most UK homes are single phase, so check your supply before choosing it. Best for Homes or small premises on a three-phase supply that want one whole-site reading on a screen. Good
Worth knowing
Who shouldn't buy it: Your home is single phase, as most are: the one-sensor kit is the match. If the supply cables are hard to reach or you are unsure which is which, ask an electrician to fit the clamps. | |||||
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Before you buy
Start with the question you want answered, because the two types answer different ones.
A smart plug with energy monitoring, such as the Tapo P110, sits between one appliance and the wall socket and tells you what that single device draws and how many kilowatt-hours it has used. That suits a hunt for an always-on drain, or settling whether an old fridge in the garage earns its keep. A clamp monitor, such as Efergy's E-Max, reads the whole house at once on a portable screen, so you can watch the total climb when the shower or oven goes on. Neither reads gas.
If you have a smart meter, pause before either.
The in-home display offered with it is free from your supplier, reads electricity and gas straight from the meter and shows the cost using your tariff. Suppliers must offer one at installation, and if yours is missing or faulty, ask them: many will replace it on request, though the terms after the first year vary by supplier. Third-party displays, such as the Glow range that pairs with the smart meter network, exist for people who want a second screen or an app, but they are a supplement to the supplier's display, not a substitute for asking for it.
For a smart plug, check the appliance against the plug's limit before you buy.
TP-Link rates the Tapo P110 and P110M at 2990W and 13A, with a motor limit of one sixth of a horsepower, so they suit fridges, freezers, dehumidifiers, televisions, computers and lamps. Check the rating plate on kettles, fan heaters, tumble dryers and anything with a large motor, which can sit at or above that limit. Both need 2.4GHz Wi-Fi and the Tapo app, and TP-Link lists both for indoor use only. The P110M adds Matter, for Apple Home, Alexa, Google or SmartThings users, and comes as four plugs.
For a clamp monitor, look at your supply before choosing a kit.
Most UK homes are single phase, which is Efergy's one-sensor E-Max; the three-sensor XL kit is for three-phase premises and larger cables, and buying it for an ordinary house pays for two clamps you cannot use. The sensor clips round the insulated live tail between the meter and the consumer unit, without any wiring, but if the cables are boxed in, hard to reach or look damaged, do not force it: ask an electrician to fit the clamp. Never open the meter or the consumer unit, and never clamp a bare conductor.
Finally, read the numbers for what they are.
A clamp-only monitor measures current and estimates power from an assumed voltage, so its figure will differ a little from the meter; the meter is what you are billed on. A smart plug measures one device directly but tells you nothing about the rest of the house. Give either a few weeks, note the baseline draw at night when the house is quiet, and then pick one change to make. If the house is still expensive to run after that, the cause is usually heating, hot water or insulation, and our heating and draught-proofing pages cover those.
We verify every product's specifications against at least two independent sources, re-check its UK price and stock on a schedule where we can track it automatically, and cross-check safety-relevant claims against official guidance. Every review is labelled Researched or Used and reviewed by us: where we've bought a product, or been sent it free, and used it ourselves, its review says which; where we haven't, our verdict is a considered spec-and-evidence comparison, not a hands-on test — and commissions never change a ranking either way. Read our full methodology →
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Common questions
Can I get a home energy monitor for free?
If you have a smart meter, often yes. Energy suppliers in Great Britain must offer a free in-home display when they install a smart meter, and if yours is missing or faulty, ask your supplier: many will supply or replace one on request. It reads electricity and gas directly from the meter and shows costs on your tariff. If you do not have a smart meter, you can ask your supplier to fit one at no upfront charge, though timing depends on your area and meter type.
What is the difference between a smart plug and a clamp energy monitor?
A smart plug with monitoring, such as the Tapo P110, meters one appliance plugged into it and shows the reading in a phone app. A clamp monitor, such as the Efergy E-Max, clips a sensor round the incoming supply cable and shows the whole house's draw on a portable screen. Use a plug to find out what one device costs to run, and a clamp to see the household total change as things switch on and off.
Do energy monitors actually save money?
Not on their own. A monitor is a measuring tool: it shows where electricity is going, and any saving comes from what you change afterwards, such as switching off an always-on device, running a dryer less or replacing an old freezer. Makers and advice bodies quote savings from their own studies; treat those as examples of what some households did, not a promise. If you already know what you would change, you may not need a monitor at all.
Is it safe to fit a clamp energy monitor myself?
The clamp is designed to clip round the insulated live cable between the meter and the consumer unit without touching any conductor, so no wiring is involved and makers sell it for home fitting. Do not open the meter, cut any seal, remove the consumer unit cover or clamp a bare wire. If the cables are boxed in, damaged, hard to identify or you are on a three-phase supply and unsure which cable is which, have an electrician fit the sensor.
What can I plug into a Tapo P110 energy monitoring plug?
TP-Link rates the P110 and the P110M at a maximum of 2990W and 13A, with motors limited to one sixth of a horsepower. That covers fridges, freezers, dehumidifiers, televisions, computers, lamps and many small gadgets. Check the rating plate on anything with a heating element or a large motor, such as kettles, fan heaters, tumble dryers, pressure washers or workshop tools, and do not use the plug beyond its stated limit. TP-Link lists both plugs for indoor use only.
Will a clamp monitor match my electricity meter?
Not exactly. A clamp-only monitor measures current and multiplies it by an assumed mains voltage to estimate power, so it will read a little above or below the meter, and the gap varies with the appliances running. It is good enough to see which devices are heavy users and how the total moves through the day. Your bill is always based on the meter, so use the clamp reading as a guide and the meter reading, or the smart meter display, for the figure that counts.
