Shelly
Shelly 3EM Smart 3-Phase Energy Meter
$121.49Cheaper
Best Home Energy Monitors · head-to-head
Shelly 3EM Smart 3-Phase Energy Meter vs IotaWatt Open WiFi Energy Monitor
A sourced, side-by-side comparison. Shelly 3EM Smart 3-Phase Energy Meter is cheaper at $121.49. Every spec and price links to its source.
IotaWatt / CircuitIQ
IotaWatt Open WiFi Energy Monitor
$389
Which is better: the Shelly 3EM Smart 3-Phase Energy Meter or IotaWatt Open WiFi Energy Monitor?
On the specs we track, they're closely matched. The Shelly 3EM Smart 3-Phase Energy Meter is the cheaper at $121.49.
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Full spec sheet
✓ marks the stronger figure where "more" — or "less", for price and weight — is unambiguously better.
| Spec | Shelly 3EM Smart 3-Phase Energy Meter | IotaWatt Open WiFi Energy Monitor |
|---|---|---|
| US price | $121.49 | $389 |
| Brand | Shelly | IotaWatt / CircuitIQ |
| Released | — | — |
| Monitoring type | ct-clamp | ct-clamp |
| Main circuit amps | 120 | — |
| Branch circuit count | 0 | 14 |
| Connectivity protocol | Wi-Fi 802.11 b/g/n | Wi-Fi |
| Solar net metering | Yes | Yes |
| Local api support | Yes | Yes |
| Subscription required | No | No |
| App platforms | iOS, Android, web | web (local) |
| Accuracy percent | — | — |
| Installation type | din-rail | panel-mount |
| Smart home integrations | Home Assistant, Alexa, Google Home, MQTT, CoAP, REST API | Home Assistant, Emoncms, PVOutput, InfluxDB |
| Etl ul certified | — | ETL (UL + CSA) |
Sources — Shelly 3EM Smart 3-Phase Energy Meter: us.shelly.com (verified 2026-06-27). IotaWatt Open WiFi Energy Monitor: stuff.iotawatt.com (verified 2026-06-27).
What's the difference between the Shelly 3EM Smart 3-Phase Energy Meter and IotaWatt Open WiFi Energy Monitor?
Where the two actually differ on the specs we track (5 of 12). Matching specs are omitted.
- Branch circuit count: Shelly 3EM Smart 3-Phase Energy Meter 0 vs IotaWatt Open WiFi Energy Monitor 14
- Connectivity protocol: Shelly 3EM Smart 3-Phase Energy Meter Wi-Fi 802.11 b/g/n vs IotaWatt Open WiFi Energy Monitor Wi-Fi
- App platforms: Shelly 3EM Smart 3-Phase Energy Meter iOS, Android, web vs IotaWatt Open WiFi Energy Monitor web (local)
- Installation type: Shelly 3EM Smart 3-Phase Energy Meter din-rail vs IotaWatt Open WiFi Energy Monitor panel-mount
- Smart home integrations: Shelly 3EM Smart 3-Phase Energy Meter Home Assistant, Alexa, Google Home, MQTT, CoAP, REST API vs IotaWatt Open WiFi Energy Monitor Home Assistant, Emoncms, PVOutput, InfluxDB