03/11/2021

KOSTAL: perfectly positioned for a growing market segment

KOSTAL provides the ideal combination of inverters and appropriate storage solutions for projects aimed at extending PV systems up to 30 kWp, a proposition that has just become very attractive thanks to the 2021 Renewable Energies Act.

The 2021 revision of the Renewable Energies Act is seriously encouraging people to buy into solar systems while also significantly increasing demand for domestic storage units for roof-mounted systems of any size. While in the past, only PV systems with an installed capacity of up to 10 kWp were exempt from the Renewable Energies Act levy on self-consumption. In the amendment of the Renewable Energies Act, this exemption is being extended to photovoltaic systems of up to 30 kWp. This opens up huge opportunities for solar self-supply as systems with heat pumps and charging stations for electric vehicles can also be installed without any levies whatsoever.

As the Bonn-based market research institute EUPD Research found in an analysis of the first quarter, the number of PV system installations of up to 10 kW has risen by almost 40 percent compared with the previous year to a total output of 215 MW. The increase in solar systems with a design capacity of 10 to 30 kW has risen by a huge 150 percent to a newly calculated capacity of 66 MW.

This marked increase in roof-mounted solar systems is accompanied by huge demand for domestic storage units. The forecast installation rate of such units has rocketed by almost 50 percent. Customers are most interested in highly efficient PV system solutions, displaying perfect harmony between PV modules, inverter and battery.

Huge demand for capacity with a storage solution

KOSTAL’s inverter partnership

KOSTAL has the perfect solution for these higher power solar systems: namely a partnership involving an inverter from the PLENTICORE plus series and an appropriate storage solution from a well-known manufacturer, such as BYD, BMZ or Nilar.

If customers opt for two PLENTICORE plus inverters in their device network, they can easily install systems of between 3 and 30 kWp. The entire PV power is then available for surplus charging of the connected battery storage unit. This makes dynamic 70-percent limitation (as required by the Renewable Energies Act) possible as well as external limitation via a ripple control receiver. Five MPPT inputs provide maximum flexibility in terms of the module design, enabling any roof orientation to be covered.

The self-learning shadow management feature of the PLENTICORE plus inverter ensures maximum yields from solar power generation. It is incredibly simple to interconnect the two inverters with the battery unit.

How to produce systems conforming to the Renewable Energies Act

The battery is connected to the more powerful of the two PLENTICORE plus when in “hybrid inverter” mode. The second inverter is easily integrated into the system as a pure solar inverter. When the “storage of surplus AC energy” function is activated, the PLENTICORE plus supplying the battery can also receive this energy on the AC side and transfer it to the connected storage unit.
The energy generated via the two inverters is then available to charge the battery. At the same time, two inverters provide a total of five PV inputs for high-performance solar operation. This guarantees sufficient power even when the sun is not shining.

Depending on the device combination, the AC power can be easily and purposefully aligned with the PV system in say 1.5 kW steps. Therefore, battery capacities of between 5 and 22 kWh can be achieved with ease.

PLENTICORE plus: great performance, great flexibility

As a three-phase hybrid device, the PLENTICORE plus is suited to both new installations and retrofits. This hybrid inverter from KOSTAL reliably delivers between 3 and 10 kW – perfect for extending a PV system with an appropriate storage unit, e.g. from BYD, BMZ or Nilar.

PLENTICORE plus with battery storage from BYD

The PLENTICORE plus is compatible with the Premium BYD high-voltage lithium battery boxes. These are quick and easy to install and deliver usable capacities of up to 21.68 kWh with a charging and discharging capacity of up to 6.5 kW. If using accessories, such as the BYD combiner box, three BYD battery towers, for example, can be run in parallel. This means that a large self-supply of high-performance consumers, such as heating, continuous-flow heaters, air conditioning systems, electric vehicles etc. is possible.

All versions of the Premium battery box can be easily and flexibly added to at any time thanks to the patented plug-in system. One storage unit contains five to nine modules with a storage capacity of 1.28 kWh. Depending on demand, the storage unit can be integrated into the PV system with an AC or DC connection. The modular structure allows the Premium BYD battery box to be extended to three battery towers when running in parallel with the BYD combiner box, offering a forward-looking capacity of up to 66.3 kWh.

PLENTICORE plus with battery storage from BMZ

Depending on the number of modules and capacity of the inverter, a maximum of up to 4 kW of power can be drawn via the BMZ HYPERION storage unit connected to the PLENTICORE plus via the RS485 interface. With the PLENTICORE plus, the usable capacity is up to 14.3 kWh. This combination of devices is therefore highly suited to operators installing their PV system from scratch and needing an inverter-battery pairing which can perfectly deliver the increased energy demand.

The maintenance-free, HYPERION high-voltage lithium battery system installed in Germany can be upgraded from its three basic modules to six modules with Helios Power battery units. The storage system also provides the very best safety: along with short-circuit and overcharge protection, integrated temperature control and passive balancing between the cell voltages, a BMS, CID and safety venting ensure smooth operation.

PLENTICORE plus with battery storage from Nilar

KOSTAL’s PLENTICORE plus hybrid inverter is the ideal conversion and control centre for linking a Nilar storage system. Nilar’s Energy Home Box storage provides perfect solutions for average and high electricity demand.

The Nilar Home Box with its compact design is perfect for safe and simple domestic installations. The 10 Ah system is designed for a 5.76 kWh capacity and, with its 1C rate, delivers a maximum continuous charge from the storage capacity available and/or discharging into the storage unit.

The flow of energy between solar modules, inverter, energy storage unit and power grid is optimised by the controller fitted inside the device and intelligent storage system software. Whenever possible, the Home Box stores excess solar energy and then makes it available later as and when it is needed. This is the perfect basis upon which to increase self-consumption from solar power while minimising grid charges.

What’s more: KOSTAL’s PLENTICORE inverter range combined with the BYD battery box has once again scored top marks in the independent tests of HTW Berlin carried out into the system efficiency of PV storage systems.

The new AutoUpdate function means that plant owners always have the very latest software version for their inverter because the devices update themselves automatically – for the best performance and maximum safety.

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