Load CAN be switched on
You can only select this option if you have a self-consumption system and use the self-generated PV energy in your own household.
Optional loads cannot be used with zero export.
The load must have a flexible switch-on time. The Sunny Home Manager switches on the load within the time period you have configured. However, the configured conditions must be met. You choose among the following conditions for configuration:
Proportion of the PV energy
You can set the load to be switched on only when a certain minimum amount of PV energy is available for its operation or is expected for a certain period of time (ecological optimization).
0% PV generation = 100% grid-supplied power
Since grid energy is always available, the load can be operated within the time period without any restrictions. However, this selection does not make sense, as self-consumption systems should aim for the highest possible self-sufficiency quota.
100% PV generation = 0% grid-supplied power
The load is switched on only if its operation can be covered by the PV power surplus. Since you directly use the energy generated by your PV system yourself, it is not fed into the utility grid and you do not receive any feed-in tariff for this PV energy.
100% PV energy not fed into the grid
If the limiting of the active power feed-in ( > Configuring Limitation of Active Power Feed-In) is activated, you can also set the proportion of PV energy not fed into the grid that would otherwise be derated.
If your system has active power limitation, active power can only be fed into the utility grid up to a predefined threshold (e.g. 70% regulation in Germany). If this value is exceeded, the PV and hybrid inverters will be regulated down. As a result, any PV energy generated above this threshold is lost as "PV energy not fed into the grid". PV energy not fed into the grid, however, can be used effectively if it is available when a load happens to be switched on. The PV energy not fed into the grid is free (0 ct/kWh) since it would not have been fed into the utility grid anyway due to the active power limitation requirements.
Sunny Home Manager also considers PV energy not fed into the grid in its PV power generation forecast. If 100% PV energy not fed into the grid is set, the load will only be switched on if the forecasted PV energy not fed into the grid can cover the total power consumption for the configured minimum switch-on time.
Maximum permitted energy costs
You can specify that the load should only be operated if the energy costs to operate the load are below a predefined cost limit (economic optimization).
In the case of exclusive use of energy from the utility grid, the costs correspond to the electricity tariff in Euro/kWh for the grid-supplied electricity that was set in the system properties.
Since grid energy is always available, the load can be operated within the time period without any restrictions.
In the case of exclusive use of self-generated PV energy, the costs correspond to the feed-in tariff in Euro/kWh that was set in the system properties.
You do not receive a feed-in tariff for PV energy if it is consumed by a load in your home instead of being fed into the utility grid. Put another way, the PV energy that could otherwise have been fed into the grid "costs" as much as the feed-in tariff.
If the set proportion of PV energy is not attained or the set maximum permissible energy costs are exceeded, it is possible that the load will not receive any energy and that the load will not be switched on at all in the defined time period.
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