SMA HM-20 User Manual

12 Load Control
SMA Solar Technology AG
Operating manualHM-20-BE-en-1972
12.1.3.1 Load MUST be switched on
The load must have a defined operating time.
SunnyHomeManager switches the load on and off within the configured time period.
You should select this option if the load should be operated in any case, for example on a specific day.
The load is also switched on if there is not sufficient self-generated PV energy available, i.e. energy required for
the load to operate may be drawn from the utility grid.
12.1.3.2 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.
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% surplus PV energy
If the limiting of the active power feed-in (see Section10.4.3, page43) is activated , you can also set the
proportion of surplus PV energy 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 "surplus PV energy". Surplus
PV energy, however, can be used effectively if it is available when a load happens to be switched on. The surplus
PV energy 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 considers surplus PV energy in its PV power generation forecast. If 100% surplus PV
energy is set, the load will only be switched on if the forecasted surplus PV energy 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.

SMA HM-20 Specifications

General

Brand	SMA
Model	HM-20
Category	Measuring Instruments
Language	English