Dynamic Rate mode is designed to optimize the behavior of the Tigo EI system when a system owner has for his home an electricity contract based on dynamic electricity rates (or tariffs).
In several countries, electricity providers offer dynamic energy tariffs subject to changes: hourly, half-hourly or various time periods based on supply and demand on the wholesale electricity market. Source of dynamic rates is EPEX Spot wholesale electricity market.
The wholesale rates shown in the Tigo EI do not include additional charges and taxes, but are useful to identify cheap or expensive electricity periods; the final price trend for the system owner will be similar to the wholesaler's one.
With dynamic rates, Peak periods and Off-Peak periods change every day.
Tigo EI system can recognize “Peak periods” (expensive periods) and “Off-Peak periods” (cheap periods) automatically and modify its behavior accordingly every day.
Dynamic rates are specific and change per country. Tigo EI system detects the wholesale tariffs for the specific country of installation of the system and operates accordingly.
1. Peak Time Periods:
During Peak Time periods, PV power is prioritized to support the load, and the battery is discharged as needed to minimize grid usage, avoiding high-tariff periods. Grid power is only drawn if the battery SOC falls below the level of “reserved energy for outage” or its max discharge rate can’t support all the loads.
Among the Peak Periods, Tigo EI identifies the “Highest Peak” periods (most expensive hours of the day).
2. Off-Peak Time Periods:
During Off-Peak Time periods, PV power is prioritized to support the load and extra PV will be used for charging the battery. The battery will not discharge to support the load. Grid power will be drawn if the PV is insufficient to support the load, but grid power will not charge the battery unless the “Charge Battery From Grid” is enabled.
Among the Off-Peak Periods, Tigo EI identifies the “Lowest Off-Peak” periods (cheapest hours of the day).
3. Allow Charge Battery From Grid
This option is disabled by default; once this option is enabled, it allows to charge battery to 100% with energy from the grid during the self-recognized “Lowest Off-Peak” periods.
4. Allow Discharge Battery to the Grid
This option is disabled by default; once this option is enabled, the battery is allowed to discharge at full power during the self-recognized “Highest Peak” periods. Battery power and PV support the load first, with any excess exported to the grid. This option is typically used when utilities offer high feed-in tariffs as rewards.
User setting:
- “Reserved energy for outage”: select a specific battery SOC percentage (optional)
- Optional enable of “Allow Charge battery from grid in Lowest Off-Peak periods” toggle. Users do not need to select the specific time periods, Tigo EI automatically will do it during the identified Lowest Off-Peak periods.
- Optional enable of “Allow Discharge Battery to the grid in Highest Peak periods”. Users do not need to specify the time periods, Tigo EI automatically will do it during the identified Highest Peak periods.
- Two toggles can be enabled/disabled independently.
Dynamic Rate mode is available in specific countries: Germany, UK, Netherlands.