Reserve battery capacity and apply peak shaving only during the periods when grid peaks affect the capacity tariff.
The capacity tariff schedule tells the SmartgridOne Controller when peak-shaving protection is needed, how much battery energy should remain available, and which grid-power thresholds control charging and discharging.
The schedule reserves battery capacity and applies peak shaving only during the periods when grid peaks are commercially important. The applicable peak calculation, averaging interval, tariff windows, and billing method are defined by the grid operator or energy contract. Confirm those rules before choosing thresholds.
Many electricity network tariffs include a capacity component. Instead of charging only for total energy consumption, the grid operator may also consider the highest power peak reached during a billing period or measurement window. A short, high import peak can therefore have a disproportionate effect on network costs.
A battery can reduce those peaks by temporarily supplying part of the site's demand. Scheduling this protection avoids reserving the entire battery all day and keeps more capacity available for self-consumption or cost optimisation outside the relevant tariff windows.
Two sites can consume the same amount of energy in a day but create very different grid peaks. A site that runs several large loads simultaneously requires more grid capacity at that moment.
For example, suppose a site should remain below a target import level during weekday mornings. When demand rises above the discharge-start threshold, the battery supplies part of the load. Once import falls below the discharge-stop threshold, discharging stops. Charging is allowed again only when sufficient grid headroom or local surplus is available.
In the commissioning interface, go to:
Settings → Advanced settings → Capacity tariff schedule
The summary shows whether the feature is enabled, the current critical reserve, whether pre-charging is active, and the number of configured rules. Select Open capacity tariff wizard to review or build the schedule.
Opening the wizard does not activate the feature. Activation happens only when Save and enable capacity tariff schedule is selected at the end.
Add one or more weekly windows. Each window combines a day selection with a start and end time. Presets are available for the full week, weekdays, weekends, and individual days. Times are selected in 15-minute steps.
The critical reserve is the percentage of total battery capacity held specifically for peak shaving. This partition protects the site when the normal operating partition has been used and grid power exceeds the configured thresholds.
A larger reserve provides more peak-shaving endurance but leaves less battery capacity for the secondary objective. A smaller reserve leaves more room for normal optimisation but may be exhausted during a long or severe peak period.
Before choosing a reserve, consider:
When Charge the critical reserve before each capacity tariff period is enabled, the controller charges the battery to the minimum state of charge plus the reserved partition before the window starts. This makes the full reserve available from the beginning of the protected period.
The four thresholds create a control band around the desired grid-power level. Separate start and stop values provide hysteresis, preventing the battery from continuously switching between charging, idle, and discharging when measured power fluctuates around one boundary.
| Threshold | What it controls |
|---|---|
| Start discharging above | Begin discharging when grid import rises above this level. |
| Stop discharging below | Stop discharging after grid import falls to the lower release level. |
| Stop charging above | Pause charging before it consumes too much grid headroom. |
| Start charging below | Allow charging again when grid import is low enough or sufficient local surplus is available. |
The thresholds must use this order:
Start charging below <= Stop charging above <= Stop discharging below <= Start discharging above
Choose All year round for one consistent target, Per quarter for seasonal groups, or Per month when network limits or operating conditions change throughout the year.
Before enabling the schedule, review every active window and threshold set. Selecting Save and enable capacity tariff schedule enables the feature and replaces the existing capacity tariff rules.
During protected periods, the controller uses the reserved battery capacity to reduce grid peaks while preserving a predictable operating band. This can reduce exposure to capacity charges, but it cannot guarantee a specific invoice because billing rules and site conditions remain external factors.
Ask for assistance if the tariff calculation is unclear, the battery reserve empties too early, charging creates a new peak, the meter sign convention is uncertain, or another control signal appears to override the schedule. Validate changes against both the electrical installation limits and the applicable network tariff.
For the underlying battery control behaviour, see Battery peak shaving.