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Description of use
The sonnen eco Gen 3.1 is an intelligent storage
system that monitors and controls energy
production, consumption, and storage in the
house.
The sonnen eco Gen 3.1 can work with existing
or newly installed PV systems. The solar inverter
and eco Gen 3.1 storage system connect to the
same distribution panel. Solar modules do not
connect to the sonnen directly.
The storage system uses two power meters
to monitor solar power production and energy
consumption. When production is higher than
consumption, such as at midday, the eco Gen
3.1 stores the excess energy in its lithium iron
phosphate (LiFePo4) battery modules. In some
operating modes, when consumption is higher than
production, such as in the evening, the storage
system releases the energy. In doing so, the storage
system allows you to use solar power at night,
reducing your power bill and increasing the value of
your investment in renewable energy.
The storage system also acts as a backup power
supply, meaning that if the utility grid goes out, your
appliances will be powered by the unit's stored energy.
The illustration below shows how the storage
system manages solar power (1) and power from
the utility grid (2) to maximize your energy
independence and savings on your power bill.
Fig. 4 Energy flow
Modes of operation
The sonnen eco Gen 3.1 offers three
complementary modes of operation: Self-
consumption, Backup, and Time of Use. Self-
consumption mode ensures that you are using
the power you generated even when utility grid
power is available; backup mode makes that self-
generated power available in the event of a grid
power outage.
Many utility companies are moving to a Time
of Use-based billing scheme, in which electricity
costs more during high-demand time periods.
The sonnen eco Gen 3.1 can maximize your cost
savings by using your stored battery power during
the high-cost part of the day and recharging from
solar and optionally with electricity purchased
from the grid during the times when the rates are
low.
Self-consumption mode
The following images illustrate the interaction
between the storage system, the PV system, and
the utility grid in self-consumption and backup
modes:
Fig. 5 Self-consumption mode
The DC power that is generated by the PV array
(A) is converted to AC power by means of an
inverter (B). The storage system’s internal meters
(C) and (D) measure the current electrical power
B
C
D
A
G
H
F
E