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PV Profiler

The PV Profiler connects your solar panels to the scheduling engine. Instead of only looking at the cheapest grid price, it lets the scheduler prefer time slots when you have solar surplus — free energy that would otherwise be exported to the grid.

When you need the PV Profiler

You should add a PV Profiler if:

  • You have solar panels on your roof
  • You want the scheduler to prefer running appliances when you have solar surplus, not just when the grid price is lowest
  • You have (or are willing to create) a free Solcast account for solar forecasts

Setting up Solcast

Power Profiler uses Solcast to get solar production forecasts for your location. You need a free account before adding a PV Profiler device.

  1. Go to toolkit.solcast.com.au and create a free Hobbyist account
  2. Add your rooftop site — enter your address, panel orientation (azimuth), tilt angle, and total capacity in kWp
  3. From your Solcast dashboard, copy your API key and your rooftop site's Resource ID
  4. In Homey, go to Apps → Power Profiler → Settings
  5. Enter the API key and Resource ID

Note

The Hobbyist plan allows 10 API calls per day. Power Profiler uses about 4 calls per day, leaving room for retries and restarts.

Adding a PV Profiler device

  1. Go to Devices → + (Add Device) → Power Profiler → PV Profiler
  2. Select your PV inverter — the device that reports how much power your solar panels are currently producing
  3. Optionally select your smart meter (P1 meter) — this enables accurate base load profiling
  4. Give the device a name (e.g., "Solar Profiler")

What you see on the dashboard

Capability What it means
Power Live PV output from your inverter (watts)
PV yield today Total energy your panels produced today (kWh)
Forecast today Corrected forecast for remaining production today (kWh)
Forecast tomorrow Corrected forecast for tomorrow's total production (kWh)
Correction factor How much your actual production differs from the generic Solcast forecast (×)
PV surplus Current power available after household base load (watts)
Return price Current feed-in tariff from your energy provider (EUR/kWh)
Grid price Current grid energy price (EUR/kWh)
Base load source Shows whether base load comes from your smart meter or the fallback value

How the correction factor works

Solcast provides a generic solar forecast based on weather data and your panel specifications. But your actual yield often differs from that prediction:

  • Nearby trees may cause partial shading at certain times of day
  • Panels degrade over time
  • Your roof orientation might not perfectly match what you entered in Solcast

The PV Profiler tracks your actual yield per 30-minute time slot and compares it to what Solcast predicted. Over time, it builds a correction factor for each slot. For example, it might learn that in the morning you typically produce 85% of what Solcast predicts, but in the afternoon it is 110%.

After about 7 days of data, the correction stabilizes and forecasts become accurate for your specific installation. During the first week, forecasts may be less accurate — this is normal.

flowchart TD
    A["☀️ Solcast API\n(generic forecast)"] --> B["🔧 Correction Engine"]
    C["📊 Actual PV Yield\n(from your inverter)"] --> B
    B --> D["📈 Corrected Forecast\n(specific to your installation)"]
    D --> E["💰 Effective Prices\n(for the scheduler)"]

Base load: with and without a smart meter

The PV Profiler needs to know your household's base load — the power consumed by everything except the appliance you are scheduling — to calculate how much solar surplus is actually available.

When you select a smart meter (P1 meter) during pairing:

  • The app reads your household's grid consumption from the smart meter
  • Base load = grid consumption + PV production (this correctly accounts for both importing and exporting)
  • The app learns your base load pattern per 30-minute slot — for example, higher in the morning (coffee, shower) and evening (cooking, TV)
  • The surplus calculation is accurate: surplus = PV production − actual base load

Without a smart meter

When no smart meter is connected:

  • The app uses a fixed fallback value (default: 400W, typical for a Dutch household)
  • This is less accurate because your actual base load varies throughout the day
  • You can adjust the fallback in device settings if 400W does not match your household

Tip

A P1 smart meter (like the Homey built-in energy module or a P1 dongle) significantly improves scheduling accuracy. If you have one, always select it during pairing.

PV Profiler settings

Setting Default What it does
Base load fallback 400 W Household base load estimate when no smart meter is connected