The emergence of dynamic or time-of-day (TOD) tariffs, following the end of feed-in tariffs (FITs) in several European countries, has spurred demand for flexible and scalable PV + energy storage solutions (ESS). sonnen GmbH, a Germany-based energy storage solution provider, put its wide range of ESS solutions on display at its booth, targeting this evolving demand in the European market at Intersolar Europe 2025.
In a short interview with Anu Bhambani, Senior Editor at TaiyangNews, Roland Burger, Senior Product Manager Device at sonnen GmbH, highlighted the storage company’s latest sB10 hybrid ESS solution.
According to Burger, this new ESS system, designed for a DC-coupled configuration, is integrated with an external hybrid inverter. Suitable for new PV installations, this ESS system can be characterized based on multiple key metrics – Performance, Flexibility & Scalability.
Performance
Burger says that the 1,000 V system voltage level external hybrid inverter, equipped with 2 or 4 MPPT channels, each with a voltage range of 80 V to 850 V, can intake PV string current not exceeding 15 A from the connected PV array. Designed to withstand up to 150% DC/AC oversizing PV array installation, this 10 kW-rated hybrid inverter can be directly connected to the battery cabinet. Equipped with Lithium Iron Phosphate (LFP) based battery cells, each battery bank, rated at 5.5 kWh, can absorb or deliver up to 2.6 kW charging or discharging power, respectively. Based on the company’s datasheet, its battery bank, engineered to have an operational temperature range of between -5°C and 45°C and a life span of up to 10,000 cycles, can be operational for a maximum of 20 years.
Flexibility & Scalability
The company offers 2 different variants of hybrid inverters, featuring 2 or 4 MPPT channels, stated Burger. This flexibility empowers consumers to choose the hybrid inverter, aligning with different orientations of the installed PV on the roof. Alongside ensuring maximum possible utilization of connected PV capacity, the company offers flexibility in upscaling energy storage capacity, based on evolving consumer demand. This ESS system can be scaled up to 27.5 kWh, which can cater to charging or discharging power not exceeding 10 kW, following the stacking of 5 similar battery units in a single battery cabinet, added Burger. Notably, the maximum charging or discharging power of the battery cabinet matches the rated capacity of the 3-phase hybrid inverter.
In terms of system design flexibility, this system requires a small installation footprint of (H × W × D) 187 × 89 × 136 cm, while the product dimension is (H × W × D) 184 × 69 × 36.
Backup Power
It can switch to backup mode within 5 seconds of a grid failure and shutdown, delivering up to 3.68 kVA AC power in each phase. The reconnection time of the system is specified for a duration of 5.5 minutes.
Commercial Availability
Regarding the market availability, Burger informed that this new product will be commercially available in Germany, Switzerland, and Austria by June 2025. Following this, it will be available in Sweden by the 2nd half of this year.
