How to Build a Home Assistant Energy Dashboard That Tracks Solar Export and Time-of-Use Tariffs

According to IAMMETER's product page, the WEM3050T is a three-phase meter that also covers single-phase and split-phase installs. It measures import and export separately, and publishes locally over Modbus/TCP, MQTT or an HTTP API, with Home Assistant support. That's exactly what a local Home Assistant install wants. IAMMETER lists the WEM3080 as its single-phase model and the WEM3080T as another three-phase option.

Electrical warning, plainly stated: fitting CT clamps around the main conductors means working inside your switchboard. Treat it as a job for a licensed electrician, not a DIY project, regardless of what an overseas YouTube video shows. Licensing and certification rules are set state by state, so check with your state or territory's electrical safety regulator (in Victoria, for example, Energy Safe Victoria covers switchboard work and certificates of electrical safety). Budget for a sparky call-out on top of the hardware cost.

A no-touch alternative may exist, depending on where you live. Some Victorian distributors let you connect an in-home display to your smart meter (Jemena's smart meter page mentions this option), and some retailers and metering providers offer usage-data portals. Whether you can get a live local feed at all depends on your meter, your metering provider and your distributor, so ask them before you buy a meter-reading gadget.

Splitting import from export correctly

This is where most first attempts go wrong. Bidirectional meters often publish a single signed power value — positive when importing, negative when exporting. The Energy dashboard needs two separate, always-increasing sensors.

Create two template sensors that split the signal:

template:
  - sensor:
      - name: "Grid import power"
        unit_of_measurement: "W"
        device_class: power
        state: >
          {{ [states('sensor.grid_power') | float(0), 0] | max }}
      - name: "Grid export power"
        unit_of_measurement: "W"
        device_class: power
        state: >
          {{ [states('sensor.grid_power') | float(0), 0] | min | abs }}

Then run each through its own Riemann sum integration helper to get sensor.grid_import_energy and sensor.grid_export_energy. Those are the two entities you point the Energy dashboard at.

If your meter already gives you separate lifetime import and export registers, skip all of this and use them directly — they'll be more accurate.

Layering time-of-use tariffs on top

Home Assistant supports two costing approaches per source: a fixed price, or an entity that tracks the current price per kWh. For time-of-use billing you want the second.

Build a template sensor that returns the right rate for the current time. As one example, at the time of writing Ausgrid's residential time-of-use network tariff has a peak from 3pm to 9pm every day in June–August and November–March, and off-peak at all other times. Ausgrid itself notes that retailers can apply different periods, and Energy Made Easy points out that some plans add shoulder periods or more. So your windows and rates are set by your distributor and retailer and will differ. Read your own bill or your plan's Basic Plan Information Document rather than copying mine. The times in the example below are illustrative only.

template:
  - sensor:
      - name: "Electricity import price"
        unit_of_measurement: "AUD/kWh"
        state: >
          {% set h = now().hour %}
          {% set weekday = now().weekday() < 5 %}
          {% if weekday and 14 <= h < 20 %}
            0.5400
          {% elif 7 <= h < 22 %}
            0.3100
          {% else %}
            0.2200
          {% endif %}

Those rates and times are illustrative examples, not real prices — replace them with the figures from your own bill or plan. Rates vary widely by state, distributor and plan; you can look up and compare plans on Energy Made Easy, or on Victorian Energy Compare in Victoria.

Do the same for your feed-in tariff and attach it to the "Return to grid" source. According to energy.gov.au, most feed-in tariffs pay a single rate, but some retailers in some areas offer variable ones. These include time-of-use feed-in tariffs, typically lower in the middle of the day and higher in the evening. Check which type your plan has. If you're on a wholesale-linked plan whose price moves through the day, an integration that pulls live pricing is a better fit than a hardcoded template.

For per-period totals rather than just costs, add a utility_meter with tariffs:

utility_meter:
  daily_grid_import:
    source: sensor.grid_import_energy
    cycle: daily
    tariffs:
      - peak
      - shoulder
      - offpeak

Then write a simple time-triggered automation calling select.select_option on the generated select.daily_grid_import entity to switch tariffs at each boundary. Now you can see exactly how many kilowatt-hours you burn in the expensive window — which is the number that actually moves your bill.

Adding device-level monitoring and load shifting

Once the whole-house picture is right, individual circuits tell you where to act. The Energy dashboard has a separate "Individual devices" section for exactly this.

Zigbee smart plugs with energy metering are the cheapest way in, and running them through a local coordinator keeps everything off the cloud and off your WiFi.