sonnenPro flexstack
The storage that
grows with your company.

Versatile applications – from commerce and industry to agriculture
Our modular system flexibly adapts to your needs: sonnenPro FlexStack enables your company to store self-produced solar energy, increase your self-consumption, and reduce grid electricity purchases in the long term. Thanks to its modular and outdoor-compatible design, the powerful FlexStack Energy Storage System meets the high demands of commercial environments. Simply choose the desired capacity – expandable in 55 kWh increments.
Reduce costs with self-generated electricity
FlexStack stores surplus energy from the PV system and provides it exactly when needed. This allows electrical consumers to be supplied with self-produced green electricity during the evening, night, and early morning hours, and prevents excess electricity from being fed into the grid.

More potential with fast charging stations
FlexStack reliably supplies electric vehicles on company premises with green electricity. The high-voltage battery storage provides a power buffer for the charging station. This also ensures supply during peak load times – making complex and lengthy grid expansion unnecessary.

Reduce CO2 emissions
By consuming more self-produced PV electricity, the reliance on energy from fossil fuels is reduced, and CO2 emissions are lowered. This allows companies to achieve their mandated climate targets significantly sooner and actively make an important contribution to society.


Maximum Power
Maximum Capacity
for full flexibility
Configurations




The sonnenPro EMS optimizes automatically
PV and storage are a powerful start. You gain the most benefit when generation, storage, and consumption work together – preventing peak loads from even occurring. The sonnenPro EMS automatically controls the sonnenPro FlexStack, maximizing your energy utilization:
- Reduce peak loads
- Optimize PV power utilization
- Manage Loads
Frequently Asked Questions
In recent years, electricity prices have continuously risen, causing increased costs, especially for businesses with high electricity consumption. A powerful energy storage system allows companies to store self-generated solar energy from their in-house photovoltaic system and increase their energy independence. A commercial storage system like the sonnenPro FlexStack reduces grid reliance and can significantly lower annual electricity supply costs. This can achieve an energy independence level of up to 70%. In addition to businesses with high electricity consumption, the FlexStack is also suitable, for example, for agricultural businesses with expiring EEG installations, as well as for businesses that want to reduce their CO₂ emissions and contribute to climate protection.
The size of the FlexStack battery storage system depends heavily on the individual circumstances and requirements of each business. Consumption profile, generation, electricity price, etc., will be clarified in a consultation to find the optimal solution for you. Thanks to its flexible design in terms of power and energy, the FlexStack is suitable for most commercial businesses as well as small to medium-sized industrial operations. Our experts will be happy to advise you in a personalized on-site consultation.
Yes, the system is IP65 certified and can be used for both indoor and outdoor installation. The prerequisites are a solid foundation and good accessibility for installation and service. Our experts will be happy to provide comprehensive advice during an on-site appointment.
Since its founding, sonnen has exclusively relied on the particularly safe lithium iron phosphate technology because we believe it delivers the best performance for our customers. When selecting our technology, we are guided by the latest knowledge, but we also rely on our own years of expertise. Therefore, we have thoroughly tested all batteries we use over long periods to guarantee maximum safety and longevity for our customers. In our specially built battery laboratory, we have gained experience in testing batteries for home storage systems since 2010 and have built up extensive know-how. We constantly test a large number of different battery technologies. However, so far, only lithium iron phosphate technology has passed our safety and longevity tests with such excellent results that its use is justified from our perspective.
No, the commercial storage system can also be operated without a PV system, for example, as additional charging infrastructure with charging stations. However, we generally recommend combining a PV system with a commercial storage system, as this application offers the greatest potential.
IP 65 protection is an international standard stating that an electrical enclosure is dust-tight and waterproof.
This standard is defined by the International Electrotechnical Commission (IEC). It describes the protection an enclosure for electrical devices offers against dust and other foreign objects, accidental contact, and water. The first digit of the IP classification indicates the degree of protection against solid foreign objects. For enclosures with IP 65 protection, the '6' is the highest level of protection against the ingress of solid foreign objects. This means the product is "dust-tight". The second digit represents the enclosure's resistance to liquids. The digit '5' in an IP 65 enclosure indicates that it is protected against low-pressure water jets and other liquids sprayed or splashed from any angle.


