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Home Assistant Energy Dashboard with Shelly

By SumGuy 10 min read
Home Assistant Energy Dashboard with Shelly

You’re Flying Blind on Your Own Electricity Bill

Right now, your home is burning kilowatts and you have no idea where they’re going. Your thermostat’s pulling 5kW heating the guest room nobody uses. Your HVAC’s ripping 8kW during peak hours. Solar’s dumping excess back to the grid at a loss. And your electricity bill arrives monthly as a punch in the gut.

Home Assistant + Shelly energy monitoring fixes this. You get real-time kilowatt visibility, per-circuit breakdowns, solar tracking, and dashboards that actually make decisions worth acting on. Not Instagram-worthy graphs—useful graphs.

Here’s the thing: you don’t need a $50K solar install or rewiring your entire house. A Shelly clamp meter on your mains costs $40 and takes 20 minutes. We’re talking real utility-grade monitoring on the cheap.

The Shelly Energy Meter Lineup

Shelly’s energy monitoring lineup is purpose-built for home labs. Let’s skip the BS and pick one that fits your setup.

Shelly EM (the one-job wonder)

Pick this if: You’re starting small, just want to see total home usage, or your electrical panel is too cramped for anything bigger.

Shelly Pro 3EM (the three-phase flex)

Pick this if: Your panel has space, you want to split monitoring (solar on clamp 1, AC on clamp 2, EV charger on clamp 3), or you’re in Europe with three-phase power. US single-phase homes should use the standard EM.

Shelly 3EM Pro (the overkill option)

Pick this if: You’re installing outside, need redundancy (dual WiFi/Ethernet), or hate yourself. Honest answer: most home labs don’t need it. EM or Pro 3EM is plenty.

What about three-phase North American setups?

If you genuinely have three-phase power at home (rare, commercial-style 208V or 277V), the Pro 3EM is your only Shelly option. More likely: you have single-phase split-service (two 120V legs, rotated 180°). That’s normal. One EM clamp goes on your main.

Wiring: The Part That Separates the Lab Nerds from the Sparky Heros

Installing a clamp meter is not electrically scary—you’re clamping around the outside of the wire, not cutting into anything. Your fingers stay on the outside. Still, “goes in electrical panel” means take 30 seconds to not be stupid.

The Safe Way (One EM on the Main)

 ┌─ Utility Meter ─┐
 │                │
 ├─ Main Breaker ─┤ ← Clamp meter's magnetic loop goes AROUND this
 │                │     (like holding a phone camera over your shoulder)
 ├─ 200A Breaker  │
 ├─ HVAC (40A)    │
 ├─ EV Charger... │
 └────────────────┘

Correct:

  1. Clamp meter’s loop slides around ONE of the main conductors (the live wire entering your home from the meter)
  2. Clamp is closed, metal core captures the magnetic field, tells you amps
  3. Shelly EM multiplies amps × 240V → watts
  4. No cuts, no breaker reset needed

If your panel’s too packed:

The “I Want to See Individual Circuits” Way (Pro 3EM Setup)

This gets juicier. You’ve got three clamps. Instead of wasting all three on your three-phase nonsense (you don’t have three-phase), use them smartly:

Clamp 1: Solar input (from your inverter, before the battery)
Clamp 2: Grid draw (main service, total consumption)
Clamp 3: EV charger (dedicated circuit for charging patterns)

Home Assistant tracks all three independently. You see solar generation, grid pull, and what the car’s actually costing you per charge. Decisions happen.

OR:

Clamp 1: Master bedroom (circuits 1–4)
Clamp 2: Kitchen (circuits 5–9, the appliance murder zone)
Clamp 3: Garage & workshop (circuits 10–12)

If your sub-panels have their own mains, one clamp per sub-panel. Now HA knows which room’s the power hog.

Home Assistant Integration

You’ve got two paths: Shelly Cloud (automated, requires registration) or Local Mode (faster, offline, no cloud handshake).

Shelly devices auto-respond on your local network. No pairing dance, no cloud dependency.

1. Find the Shelly’s IP (on your router):

2. Enable authentication (optional but do it):

3. Add to Home Assistant:

configuration.yaml
shell:
  - host: shelly-em.local
    username: admin
    password: !secret shelly_password

Restart HA. Home Assistant auto-discovers the Shelly’s sensors:

Expose the Energy Sensor

Home Assistant’s built-in Energy Dashboard looks for entities tagged as energy:

configuration.yaml
homeassistant:
  customize:
    sensor.shelly_em_energy:
      unit_of_measurement: "kWh"
      device_class: "energy"
      state_class: "total_increasing"

The state_class total_increasing tells HA: “this value only goes up, reset it for daily totals.” HA handles the monthly/yearly breakdown automatically.

Multi-Clamp Setup (Pro 3EM)

If you’re using a Pro 3EM with three clamps, each clamp gets its own sensor:

homeassistant:
  customize:
    sensor.shelly_pro_3em_emeter_0_power:
      friendly_name: "Solar Input"
    sensor.shelly_pro_3em_emeter_0_energy:
      friendly_name: "Solar Generated"
      device_class: "energy"
      state_class: "total_increasing"


    sensor.shelly_pro_3em_emeter_1_power:
      friendly_name: "Grid Draw"
    sensor.shelly_pro_3em_emeter_1_energy:
      friendly_name: "Grid Imported"
      device_class: "energy"
      state_class: "total_increasing"


    sensor.shelly_pro_3em_emeter_2_power:
      friendly_name: "EV Charger"
    sensor.shelly_pro_3em_emeter_2_energy:
      friendly_name: "EV Charged"
      device_class: "energy"
      state_class: "total_increasing"

Each now appears as its own entry in the Energy Dashboard.

The Energy Dashboard: What It Actually Tells You

Home Assistant’s Energy tab (left sidebar, if you’ve enabled it) visualizes:

Grid Consumption (today, this week, this month)

Solar Production (if you have panels)

Individual Appliances (if you get fancy)

Cost Tracking

The catch: Data only flows backward as far as your Shelly’s been running. Day 1 shows nothing. Week 1 shows daily averages. Month 1 shows the first full month. HA’s database persists locally, so you’re never losing history to cloud nonsense.

Real Example: The Setup That Actually Works

Let’s say you’ve got a 200A service, a tiny solar array (5kW inverter), and an EV charger.

Hardware:

Physical install:

HA config:

homeassistant:
  customize:
    sensor.shelly_pro_3em_emeter_0_power:
      friendly_name: "Solar Now"
    sensor.shelly_pro_3em_emeter_0_energy:
      friendly_name: "Solar Today"
      device_class: "energy"
      state_class: "total_increasing"


    sensor.shelly_pro_3em_emeter_1_power:
      friendly_name: "Home Draw"
    sensor.shelly_pro_3em_emeter_1_energy:
      friendly_name: "Grid Imported"
      device_class: "energy"
      state_class: "total_increasing"


    sensor.shelly_pro_3em_emeter_2_power:
      friendly_name: "EV Power"
    sensor.shelly_pro_3em_emeter_2_energy:
      friendly_name: "EV Charged"
      device_class: "energy"
      state_class: "total_increasing"

Result: Your Energy Dashboard now shows:

You see that charging the car at 10 PM costs $3 in grid power. Charging at 2 PM cost you $0.40 (all solar). Decision made: set the EV charger automation to favor solar windows.

Common Gotchas (So You Don’t Debug For Four Hours)

“My Shelly reports zero power”

Clamp’s probably not around the right conductor. Flip the clamp around the other leg—if one leg has zero, the other has 240V.

Or: clamp isn’t closed tight. The magnetic loop needs full contact. It should click shut.

”Sensor data updates every 30 seconds, not real-time”

Default polling interval is 30s. If you need sub-second granularity (rare), increase the Shelly’s update frequency in its local web UI. Fair warning: kills battery life if you’re ever wireless-only (most home labs have PoE’d Shellys, so no issue).

”My daily energy reset at 11 PM, not midnight”

Home Assistant’s timezone is wrong. Check:

homeassistant:
  time_zone: America/New_York  # or whatever

Redeploy. The Energy Dashboard respects this for daily boundaries.

”Pro 3EM shows all three clamps at the same value”

You probably got the clamps swapped in the UI. Shelly’s web panel lets you relabel them. Go to http://shelly-pro-3em.local, Meters → Channel labels. Swap back. The values won’t change; HA just displays them to the right sensor name.

The Decision Tree: Which Shelly for You

Just want to see total home power: → Shelly EM ($40). Clamp it on your main. Done.

Want solar + grid + EV visibility: → Shelly Pro 3EM ($90). Three clamps. Clamp solar, grid, charger.

Got a multi-building setup or sub-panels: → Two Shellys (EM or Pro 3EM) on each main. Home Assistant merges the data. Costs more, but worth the circuit-level truth.

Live in EU / three-phase is your life: → Pro 3EM is mandatory. Your clamp counts are different anyway.

Outdoor install / weatherhead mounted: → Shelly 3EM Pro (IP67). Costs $130 but you won’t watch it rust.

One More Thing: You’re Now the Grid Observer

With Shelly on the wall and HA watching, you’ve got better power visibility than your utility’s online portal. You see sub-minute swings, appliance patterns, waste in real time.

Most people see this data once and go quiet. Then, slowly: “Wait, the water heater runs for how long?” or “That HVAC’s drawing during peak pricing why?” Automations follow. Smart load-shifting happens. Your next electricity bill’s 10–20% lower.

You’ve got a forklift-level tool for moving a couch (kidding, the Shelly’s elegant), but the point is it works. Plug it in, mount it, watch the electrons.

Your 2 AM self will appreciate the decisions this dashboard lets you make.

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