With the standard Flexible Storage System if there is a power cut from the grid then the PV system and Sunny Island will shut down and the household loads will no longer be supplied.
However, by the addition of an extra automatic transfer switch the SMA Flexible Storage System can be given battery backup function, so that the existing PV system will be able to maintain the electricity supply throughout a grid failure.
For detailed information see: SMA Flexible Storage System with Battery Backup Planning Guidelines
With earth switching compliant with G99 these allow you to store excess generation from grid connected wind or PV systems not only for use at night or but also in a power cut.
Why implement grid backup?
- Get security for the future - from power cuts and rising energy bills
- Have the ability to use most or all of your generation - your energy costs less than importing grid energy
- Bask in the knowledge that you are your own power station.
Larger battery stores are generally required for backup systems than for smart storage solutions. They should be sized to cover the loads required during a power cut for the likely length of time of a power cut.
- With an SMA Flexible Storage System with battery backup function, the existing PV system will be able to maintain the electricity supply throughout a grid failure.
The battery of the SMA Flexible Storage System not only takes care of the intermediate storage of PV energy, but also supplies the loads during grid failure. The service life of the battery is hardly affected by this dual utilization as long as the utility grid is basically stable.
The maximum PV inverter power that can be connected in battery backup mode is 9.2kW per Sunny Island 6.0H or 12kW per Sunny Island 8.0H.
SMA Battery Backup Distribution Switch Boxes
Automatic transfer switches, suitable for the SMA 'Flexible Storage System' which allow operation to continue in case of main power blackouts. Contactors ensure compliant earth switching.
Certified for TT- and TN-S grids
Can be used in combination with SMA – Sunny Island 4.4M/6.0H/8.0H.
Requires SMA Home Manager 2.0 (HM-20) - not included.
SI-BBD-2 is used with one Sunny Island on 1 phase and couples the 3 phases to be backed-up in the event of a power cut.
SI-BBD-3 & SI-BBD-4 are used with three Sunny Islands (one per phase) for full 3 phase back-up.
Note: To meet the requirements of BS7671 SI-BBD-3 should be installed in an additional metal enclosure.
|Product Code||Description||Retail Price
|SI-BBD-2||3ph G99 switch box 20kW inc ph coupling (ex HM-2.0)metal enc||£1,264.09|
|SI-BBD-3||3ph battery backup G99 switch box, 35kW (exc HM-2.0)||£1,842.31|
|SI-BBD-4||3ph battery backup G99 switch box, 45kW exc HM-2.0 metal enc||£1,899.77|