Shelly or Eastron for Home Assistant: Which Energy Meter Should You Choose?
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The short answer: if you just want to see what your home uses in Home Assistant, a Shelly is the easier choice. It clips round a cable and connects over Wi-Fi. Choose an Eastron meter if you need readings you can bill someone with, want a wired connection that doesn't depend on Wi-Fi, or want a meter your solar inverter or battery system can read too. If you have a SMETS2 smart meter and only want whole-house figures, you may not need a new meter at all.
Shelly and Eastron side by side
| Shelly EM Gen3 / Pro 3EM | Eastron SDM230 / SDM72D-M / SDM630MCT | |
|---|---|---|
| How it measures | Clip-on CT clamps round the cable | Wired in line (SDM230, SDM72D-M) or with CT clamps (SDM630MCT) |
| How it talks to Home Assistant | Wi-Fi (the Pro 3EM also has Ethernet), found automatically by Home Assistant's Shelly integration | Two data wires (Modbus RS485) to a USB adapter on the Home Assistant machine |
| Extra hardware needed | None | A USB to RS485 adapter |
| Accuracy | Shelly states ±2% for the EM Gen3 and ±1% for the Pro 3EM across most of the range, less accurate at very low current | Class 1 or better, and MID approved for billing |
| MID approved for billing | Shelly doesn't list MID approval for these models | Yes |
| Works without Wi-Fi | The EM Gen3 needs Wi-Fi; the Pro 3EM can use a network cable | Yes, no network needed |
| Fitting | Needs a mains supply for the meter itself, so in practice an electrician fits it | Fitted by an electrician; the SDM230 and SDM72D-M are wired into the circuit |
Choose a Shelly if
- you want to see your whole-house use, and perhaps your solar, without breaking into any cables. The EM Gen3 has two clamp channels, so one can watch the grid and the other your solar;
- good Wi-Fi reaches your consumer unit;
- you don't need to charge anyone for the electricity you measure.
Shelly meters are well supported in Home Assistant and quick to set up. For plain monitoring, they are a sensible choice.
Choose an Eastron if
- you bill anyone for electricity: a tenant, an annexe, a holiday let or an EV driver. Billing needs a MID-approved meter. Our guide What does MID approved mean? explains the rules;
- you want a wired connection. Readings travel over two data wires, so a weak Wi-Fi signal in a garage, outbuilding or metal cabinet doesn't matter;
- you want one meter for several systems. Many solar inverters, battery systems and building controllers read Modbus meters, so the same meter can serve them and Home Assistant;
- you're an installer who wants the same meter on every job, with a MID certificate for each one.
Which Eastron meter
- Single phase: the Eastron SDM230, up to 100A, wired in line. £36.99, or £209.99 for six.
- Three phase up to 100A: the Eastron SDM72D-M, wired in line. £60.99.
- Three phase over 100A, or where you can't break into the cables: the Eastron SDM630MCT with clip-on CT clamps, from £124.99 for the meter alone.
Each one needs a USB to RS485 adapter (£15.99) to connect to Home Assistant. Our guide Which Eastron meter do I need? compares them in detail.
Already have a smart meter?
If you have a SMETS2 smart meter and only want whole-house figures, a Hildebrand Glow in-home display can pass your smart meter's readings to Home Assistant without anyone touching the wiring. It can't measure a single circuit, such as an EV charger or an annexe, and it isn't something you can bill a tenant from. For either of those you need a meter on that circuit.
The complete kit, from one supplier
If you want the Eastron route without sourcing the parts yourself, OmniKit's Home Assistant Energy Monitoring Kit (£179.99) puts everything in one box:
- a Raspberry Pi 4 Model B 8GB in a DIN rail case;
- an Eastron SDM230 MID energy meter;
- a USB to RS485 adapter;
- an industrial power supply;
- an industrial memory card with Home Assistant already installed;
- DIN rail mounting hardware.
The meter, the Pi and the power supply all mount on the same DIN rail. It isn't fully plug and play: once the meter is fitted, you add a short Modbus section to Home Assistant. Our step-by-step guide How to connect an Eastron SDM230 to Home Assistant has the settings to copy and paste. The kit is single phase; for three phase, pair a Raspberry Pi with an SDM72D-M or SDM630MCT instead.
Common questions
Can I bill a tenant from a Shelly?
Not if the meter isn't MID approved, and Shelly doesn't list MID approval for the EM Gen3 or Pro 3EM. Use a MID-approved meter, such as an Eastron, on the circuit you charge for.
Is an Eastron harder to set up in Home Assistant?
A little. You run two data wires to a USB adapter and add a short Modbus section to Home Assistant's configuration (see Home Assistant's Modbus documentation), instead of the meter appearing on its own. Once it's done, there's no Wi-Fi to drop out.
Can I use both?
Yes. Some people use an Eastron on the circuits they bill for, or where Wi-Fi won't reach, and Shellys elsewhere. Home Assistant's Energy dashboard can take readings from both.
Do I need an electrician?
For either meter, yes. Both connect to mains wiring in your consumer unit or distribution board, so they must be fitted by a competent person to the current UK wiring regulations.
Which is more accurate?
Both are accurate enough for monitoring. The Eastron meters are tested to the MID billing standard, which is the one that counts if money changes hands.
Not sure which suits your job? Email customersupport@omnikit.co.uk with your supply type and what you want to measure, and we'll tell you.