Changing the Battery Usage Regarding Systems for Increased Self-Consumption Without a Battery Backup Grid
Qualified person
Ranges for battery use:
In systems for increased self-consumption, 1 range can be adjusted seasonally:
Increased self-consumption range (SlfCsmp)
You determine the percentage of the battery capacity that is to be used for increased self-consumption on the shortest day of the year.
The longer the days become, the more the SlfCsmp range increases automatically and the range for protection against deep discharge (BatRes) decreases. The range for increased self-consumption reaches its maximum on the longest day. This results in the seasonal progression of the ranges.
State of charge ranges of the battery according to the time of year (example)
Range | Explanation of the range and parameters | Behavior of the Sunny Island inverter |
|---|---|---|
A | Self-consumption range (SlfCsmp)1) The SlfCsmp range applies to the shortest day of the year with seasonal adjustment ( > Seasonal Adjustment of the Battery Usage). When seasonal adjustment is deactivated, only the SlfCsmp range is used and the BatRes range increased accordingly. | The Sunny Island uses the battery for increased self-consumption. |
Battery > Ranges of application > Minimum width of backup power range | ||
B | State of charge conservation range (PVRes) The range size is constant year-round. | Excess PV energy is used for conserving the battery charge. If no excess PV energy is available, the Sunny Island switches to energy saving mode. When the state of charge reaches the BatRes range limit, the Sunny Island charges the battery up to half of the PVRes range from the utility grid. To do so, the Sunny Island charges the battery with maximum efficiency at 25% of the nominal power of the Sunny Island inverter. |
Battery > Ranges of application > Width of the range for conserving battery state of charge | ||
C | Deep discharge protection range (BatRes) This range can only be reached when the utility grid fails. The BatRes range applies to the longest day of the year with seasonal adjustment ( > Seasonal Adjustment of the Battery Usage). If seasonal adjustment is deactivated, the BatRes range is increased accordingly. | If a utility grid is available, the Sunny Island charges the battery using nominal power from the utility grid. |
Battery > Ranges of application > Minimum width of deep discharge protection range | ||
D | Deep discharge range (ProtRes) This range can only be reached when the utility grid fails. | When this range is reached, the Sunny Island switches off in order to protect the battery. When the utility grid is available again, the system must be charged manually. |
Battery > Ranges of application > Lower lmt deep disch. protect range prior shutdown |
1) This range can be adjusted for all battery types.
The following ranges result from the parameter default values:
Range | Lithium-ion battery | |||
|---|---|---|---|---|
Shortest day2) | Longest day3) | Shortest day2) | Longest day3) | |
Self-consumption range | 65% to 100% | 45% to 100% | 30% to 100% | 10% to 100% |
State of charge conservation range | 60% to 65% | 40% to 45% | 25% to 30% | 5% to 10% |
Deep discharge protection range | 10% to 60% | 10% to 40% | 3% to 25% | 3% to 5% |
Deep discharge range | 0% to 10% | 0% to 10% | 0% to 3% | 0% to 3% |
2) December 21 (northern hemisphere) or June 21 (southern hemisphere)
3) June 21 (northern hemisphere) or December 21 (southern hemisphere)
The following ranges result from deactivating seasonal adjustment with the default values of the parameters:
Range | Lead-acid battery | Lithium-ion battery |
|---|---|---|
Self-consumption range | 65% to 100% | 30% to 100% |
State of charge conservation range | 60% to 65% | 25% to 30% |
Deep discharge protection range | 10% to 60% | 3% to 25% |
Deep discharge range | 0% to 10% | 0% to 3% |
Parameters for battery use:
If the values for the battery usage ranges are incorrect, no adjustment is possible
If all battery usage ranges combined exceed 100%, the parameters for battery usage cannot be set.
- Ensure that all battery usage ranges combined result in the value 100%.
Parameter | Value |
|---|---|
Lower lmt deep disch. protect range prior shutdown | Range for protection during deep discharge as a percentage of the battery capacity |
Minimum width of deep discharge protection range | Range for protection against deep discharge on the longest day of the year as a percentage of the battery capacity Within this range, the system goes into energy-saving mode and automatically attempts to recharge the battery from available PV energy. The range remains constant year-round when seasonal adjustment is deactivated. |
Width of the range for conserving battery state of charge | Range for maintaining the state of charge of the battery as a percentage of the battery capacity |
Minimum width of own consumption range | Range for increasing self-consumption on the shortest day of the year as a percentage of the battery capacity When seasonal adjustment is deactivated, this value is used year-round for increased self-consumption. |
Highest-yielding month for battery utilization range: | June profitable for northern hemisphere4) |
December profitable for southern hemisphere5) | |
Season operation active | No for no seasonal adjustment or Yes for seasonal adjustment |
4) Set the value to June profitable when June is the month with the highest yield.
5) Set the value to December profitable when December is the month with the highest yield.
The basic procedure for changing operating parameters is explained in another section ( > Changing Operating Parameters).
Procedure:
- Select Device > Device > Self-consumption.
- Set the parameter Rise in self-consumption switched on to Yes.
- Select Battery > Ranges of application >.
- Set the parameters for battery use.