Portfolio Category: On-Grid

The property is a winery with an air-conditioned warehouse. The use of the SmartEnergy + DC storage solution minimizes the energy costs from the grid and ensures an isolated operation in case of mains failure. The AC output power of the system is 24kVA 3-phase. The PV generator has a total power of 26.5kWp and the battery bank has a gross capacity of 140kWh. An Air conditioning unit with approx. 16kW as well as smaller consumers, such as lighting, pumps, etc. have to be supplied.

The system is equipped with a grid & plant protection device in case grid injection is desired in future. Furthermore, the system has an uninterrupted bypass circuit to maintain the power supply in case of maintenance or a faulty system component.

SEI AG has carried out the entire planning and delivered all components of the power system. The installation was carried out by our partner in France, Conception Connect Service, Mr. Wrubel

Open installation based on the SmartEnergy + DC 5048VS for a residential house in Karlsruhe. The system consists of an XTH8000-48 and 2 VarioStrings, each connected to a 3.5kWp PV generator, an 800Ah OPzV tubular plate battery and sub-distributors (not shown on the picture) with uninterrupted bypass circuit and phase coupling. The system is completely off-grid capable and serves primarily to increase own consumption. During the summer months almost 100% self-sufficiency is achieved with the installed photovoltaics.

This object is a house in Freiburg with 3 separate apartments. The investment was made by the owners’ association. The client’s desire was to integrate the existing PV system with grid feed inverters in an off-grid-enabled storage system for self-consumption increase. The customer has placed great emphasis on ensuring that in future no energy is fed back into the grid and a grid autonomous operation is possible when needed. For this reason, the existing feed-in inverters (Sunny Boy 5000TL and Sunny Boy 1200) were replaced by a Studer VarioTrack 65 and a Studer VarioString 120. Together with the Xtender, the charge controller is operated in the DC-Priority mode and provides optimal operation in parallel to the public grid. By 2 MPP-trackers and the high input voltages of the VS-120, the existing PV generator 1 could be connected directly to the VarioString without changing the stringing. Only 2 additional branch connectors were attached to the PV generator 2, not to exceed the max. input voltage of the VT65 of 150V.

Due to the low feed-in tariff and a feedback control of 60%, a power feedback is no longer attractive for most operators. Also the program imposed by the KfW and the Federal Ministry of Environment for funding storage solutions can not hide this. To meet the criteria of the program, there are not only a lot of technical requirements to meet, which increase the costs of the systems, but you must also obligate yourself to reduce the regenerative power supply output to 60% over the 20 years. Once installed you cannot participate in local decentralized producer groups anymore, which will be playing an increasingly important role in the future.
For these reasons, we have developed our SmartEnergy + DC PV solutions. The system is a combination of battery inverter and MPPT charge controller. The power of the solar panels is stored on the DC side in the battery, only with minimal losses. The energy which is directly used flows through the inverter to the consumers. The power is only drawn from the power network when the usable energy of the battery is depleted and the current PV capacity is no longer sufficient.

The SmartEnergy+ DC systems are more than just a storage solution. They are full off-grid systems that can be operated completely independently from the power network. In case of power failure, the system switches to off-grid operation without interruption. Since the power is created on the DC side, the full PV power for charging the batteries is still available, regardless of the size of the selected battery inverter.
All systems are equipped with an automatic and manual bypass switch. During maintenance work or in case of a defect, a continuous supply of the consumers is guaranteed from the power network.
In this case the customer from Thuringia/ Germany decided on a 3-phase system of 6.1 kWp PV power. The total battery capacity is 22.5 kWh. The batteries are long lasting tubular plate batteries in the closed version (OpzV). The life expectancy at 50% discharge is >12 years.
The switch cabinet was completely pre-assembled and tested by SEI AG. This allowed quick and easy installation on site.
The SmartEnergy+ DC is also available in a 1-phase version. By phase coupling, all three phases can also be covered. The transfer of power is 11.5 kW. In case of power failure, of course only the rated power of the generator battery is available.