Solar Forecast Setup
The Charge strategy supports a solar forecast goal. Instead of charging to a fixed energy level, it calculates how much grid charging is actually needed to charge the battery to its cutoff capacity, based on today’s expected solar production. It automatically switches to solar charging (Charge PV) when it hits the calculated level. This way you optimise self-use and prevent unnescesarry exports to grid.
How It Works
When the charge goal is set to solar forecast, a dashboard distribution card shows the split between grid charge and expected solar charge.
- If the forecast covers the full battery capacity, no grid charging is needed.
- If the forecast only partially covers it, only the remaining portion is charged from the grid.
solar_surplus ~= forecast_today − reserved_for_house
charge_target ~= max_battery_energy − solar_surplus
This calculation updates automatically whenever any input changes (forecast value, threshold, or battery capacity).
Step 1 - Prerequisites
You need a solar forecast integration installed in Home Assistant that provides a daily kWh sensor. Common options:
| Integration | Sensor example |
|---|---|
| Solcast | sensor.solcast_pv_forecast_forecast_today |
| Forecast.Solar | sensor.energy_production_today |
| Open-Meteo Solar Forecast | Varies by configuration |
Any sensor that reports today’s expected solar production in kWh will work.
Step 2 - Configuration
- On the dashboard, set the Charge goal to
solar forecast. - Under Configure your solar forecast, enter your forecast sensor entity IDs:
- Solar forecast sensor (kWh today) — e.g.
sensor.solcast_pv_forecast_forecast_today - Solar forecast sensor (kWh tomorrow) — e.g.
sensor.solcast_pv_forecast_forecast_tomorrow
- Solar forecast sensor (kWh today) — e.g.
- Set Solar reserved for house (
house_battery_solar_reserved_for_house) to your estimated daily household consumption in kWh. Only solar production above this value is considered available for battery charging.- 30% of your average daily household energy use as a good starting point.
Step 3 - Tips
- Start with a conservative Solar reserved for house value (e.g. your average daily consumption). You can fine-tune it over time.
- The forecast goal works well with the Dynamic strategy: during cheap hours it charges only what solar won’t cover, saving grid costs.
- Use forecast remaining today instead of forecast today, if you want to accuratly charge at late times during the day.
- e.g.
sensor.solcast_pv_forecast_forecast_remaining_today
- e.g.
Dashboard Indicators
When the solar forecast goal is active, the dashboard shows:
| Card / Field | Description |
|---|---|
| Charging until reserve is | The calculated charge target in kWh |
| Distribution card | Visual split: available energy, grid charge portion, and solar charge portion |
| Solar forecast today | Raw forecast value from your sensor |
| Solar surplus today | Forecast minus household reservation |
| Surplus covers capacity | Whether solar alone can fill the entire battery from flat to full |
All values update in real time when the forecast, threshold, or battery capacity changes.
Entities Reference
| Entity | Type | Description |
|---|---|---|
sensor.solar_forecast_today |
Template sensor | Solar forecast mirrored from your configured sensor |
sensor.solar_forecast_surplus_today |
Template sensor | Forecast minus household consumption threshold |
sensor.charge_target_energy |
Template sensor | Calculated charge target considering solar surplus |
sensor.charge_grid_energy_portion |
Template sensor | Energy that needs to come from the grid |
sensor.charge_solar_energy_portion |
Template sensor | Energy expected from solar |
input_number.house_battery_solar_reserved_for_house |
Input number | Estimated daily household consumption |
input_number.house_battery_strategy_charge_target_energy |
Input number | Manual charge target (used by energy reserve goal) |