Shelly
Shelly EM Gen3 Energy Meter (50A CT clamp)
- Native integration
- Local control
- Wi-Fi
- Bluetooth
Prices verified September 2026
See more smart plugs & energy picks on our Amazon storefront →Our verdict
The step beyond plug-level monitoring: a CT-clamp meter that sits in your consumer unit and feeds two circuits' worth of power into HA's Energy dashboard via the core Shelly integration — all local, no subscription. Compare that to the Hildebrand Glow: Glow reads your actual smart meter register for one whole-home import/export figure, while the EM Gen3 clamps onto specific cables you choose — grid tails, a solar inverter, an EV charger — so it's more flexible but per-circuit rather than automatically whole-home. Shelly quotes ±2% current accuracy rather than a formal IEC class. Needs an electrician unless you're confident around the consumer unit.
What can Home Assistant control on the Shelly EM Gen3 Energy Meter (50A CT clamp)?
| Control | Type | What it does |
|---|---|---|
| Power (per channel) | Sensor (W) | Instantaneous active power; reads negative when that channel is net-exporting, e.g. the solar channel during daylight generation. |
| Energy consumed | Sensor (kWh) | Cumulative energy drawn from the grid on that channel; assign to the Energy dashboard's grid-consumption slot. |
| Energy returned | Sensor (kWh) | Cumulative energy exported/returned on that channel; assign to the Energy dashboard's return-to-grid or solar-production slot. |
| Reverse CT direction | Config (per channel) | Flips a channel's sign in software when its CT clamp was fitted backwards, avoiding a physical re-clamp in the consumer unit. |
| Voltage / current / power factor | Sensor | Diagnostic readings alongside power/energy; a near-zero reading on an active circuit typically indicates the CT is clamped on neutral rather than live. |
Each channel exposes a signed instantaneous power sensor plus two separate cumulative energy counters — consumed and returned — rather than one net figure, because HA's Energy dashboard config wants distinct grid-consumption and return-to-grid sensors, not a value that just goes negative on export; the solar-feeding channel's returned-energy entity plugs straight into that slot. Community reports on Shelly EM devices confirm a mis-oriented CT clamp flips a channel's sign entirely, and Shelly's own troubleshooting handles this with a per-channel reverse-direction toggle in the web UI rather than requiring a physical re-clamp. It's worth spot-checking after firmware or HA core updates that both consumed and returned entities remain present and incrementing independently, since sibling Gen3 metering devices have shipped bugs where the two got summed into one counter.
Specs
| channels | 2 |
|---|---|
| ct clamp | 50A included; optional CT80A clamp available for higher-current circuits (jaw/cable-diameter limits not published by Shelly) |
| dimensions | 37 x 42 x 16mm, 23g (device only, excludes CT clamps) |
| hub required | false |
| installation | Wall/electrical-cabinet mount inside or beside the consumer unit — not a clip-on DIN rail unit itself, but small enough to fit in a DIN enclosure alongside DIN-rail gear |
| data retention | At least 10 days of local 1-minute-resolution data on-device |
| current accuracy | ±2% (2-50A), ±2% (1-2A), ±5% (0-1A) per Shelly's published figures — no formal IEC accuracy class stated |
| voltage accuracy | ±2% |
| energy monitoring | true |
| measurement range | 0-80A per channel; 110-240V AC, 50/60Hz |
How does the Shelly EM Gen3 Energy Meter (50A CT clamp) compare?
| Product | From | Protocol | Local control | Integration |
|---|---|---|---|---|
| Shelly EM Gen3 Energy Meter (50A CT clamp) (this product) | £55.99 | Wi-Fi, Bluetooth | Yes | Native |
| Aqara Power Plug H2 UK (RGB) | £32.99 | Zigbee, Thread, Matter, Bluetooth | Yes | Works with HA |
| Aqara Wall Outlet H2 UK | £67.99 | Matter, Thread, Zigbee | Yes | Native |
| Eve Energy (Matter) UK Smart Plug | £39.95 | Thread, Matter, Bluetooth | Yes | Works with HA |
Frequently asked questions
- Does the Shelly EM Gen3 Energy Meter (50A CT clamp) work with Home Assistant locally?
- Yes. The Shelly EM Gen3 Energy Meter (50A CT clamp) is controlled locally in Home Assistant through a built-in Home Assistant core integration (shelly), so it keeps working if your internet connection or the Shelly cloud goes down. Control and state updates stay on your own network.
- Which protocol does the Shelly EM Gen3 Energy Meter (50A CT clamp) use, and do I need a hub?
- The Shelly EM Gen3 Energy Meter (50A CT clamp) uses Wi-Fi and Bluetooth. To pair it with Home Assistant you need no hub — it joins your Wi-Fi network directly; or a Bluetooth adapter on your Home Assistant host or an ESPHome Bluetooth proxy. Shelly's own hub is not required when you integrate through a built-in Home Assistant core integration (shelly).
- How much does the Shelly EM Gen3 Energy Meter (50A CT clamp) cost in the UK?
- The lowest price we have listed for the Shelly EM Gen3 Energy Meter (50A CT clamp) is £55.99 at Shelly Store UK. Prices were last checked in September 2026 and change often, so confirm on the retailer's page before buying.