KOSTAL Pressebereich


Multi-award-winning: KOSTAL inverters excel in the 2022 SPI

KOSTAL inverters once again prove what they are capable of in the HTW Berlin's 2022 Energy Storage Inspection

Renewed success: in this year's System Performance Index (SPI), when combined with BYD battery storage systems, KOSTAL inverters once again achieved top marks and demonstrated their outstanding properties.

All SPI awards at a glance:

  • PLENTICORE plus 5.5 kW came third in the outstanding energy class A
  • PLENTICORE BI 10 kW with HVS storage 12.8 was the best three-phase AC system
  • PLENTICORE plus 10 kW with HVS 12.8 battery storage achieved a great ranking among the top 5 in its power class
  • PIKO MP plus 4.6-2 with HVS 7.7 battery storage came in an excellent second in the overall evaluation of all single-phase AC-coupled systems
  • KOSTAL impresses the judges with all-round flexible solutions: both AC and DC systems as well as single- and three-phase devices
  • Existing KOSTAL customers also stand to gain from the auto-update function

How KOSTAL customers can benefit in one click

The HTW 2022 inspection shows that KOSTAL inverters, combined with storage solutions from BYD, are an optimum solution. PLENTICORE plus, PLENTICORE BI and PIKO MP plus were once again able to prove their superlative performance. For efficient PV system operation, KOSTAL and BYD respond fully to what customers want from a high self-consumption proportion - good power, high efficiency levels with minimal conversion losses and low standby consumption. In addition, the devices are quick and easy to control, resulting in even greater efficiency. High solar power yields and the best possible self-consumption rates can be achieved with inverters from KOSTAL and BYD storage units.

Activate the auto-update function now

The auto-update function also allows existing customers of a PLENTICORE plus or PLENTICORE BI to benefit from the SPI award. By simply activating the auto-update function, the KOSTAL inverters are automatically equipped with the latest software, without customers having to do a thing. The inverter is therefore always at the cutting edge of technology and, as the test was able to demonstrate, guarantees the best performance at all times.

Always up-to-date with the KOSTAL auto-update function: watch the video and activate without delay


A brief introduction to all award-winning KOSTAL invertersv

PLENTICORE plus 10: top charging and discharging performance

The KOSTAL hybrid inverter PLENTICORE plus 10 kW achieved a System Performance Index of 93.7 when combined with the BYD Battery Box Premium HVS 12.8. The control and dimensioning losses recorded during the test were minimal, while the usable storage capacity of 12.3 kWh is very good.

High efficiency levels for the battery and the PV2BAT and BAT2AC conversion of around 96 percent each ensure high charging and discharging performance.

With this result, the PLENTICORE plus 10 achieved a high ranking among the top 5 in its power class.

PLENTICORE BI 10/26: large storage unit for powerful consumers

The 10 kW/26 amp version of the PLENTICORE BI AC battery inverter with a connected Premium HVS 12.8 BYD Battery Box was able to win over the judges with its great efficiency. KOSTAL demonstrated very good system efficiency here in the SPI with a strong 92.7 percent, once again confirming the excellent performance of the battery inverter. PLENTICORE BI 10 kW/26 – the battery inverter for powerful consumers.

The KOSTAL BYD system exhibits the lowest losses during charging and discharging, regulation and energy management. The usable battery capacity of this configuration is over 12 kWh. The 10 kW battery inverter enables fast charging and discharging and its excellent conversion efficiency (battery to AC grid) of 96 percent minimises transmission losses.


In the 2022 SPI, the PLENTICORE BI 10/26 achieved the best result for usable storage capacity among all AC-coupled systems in the 10 kW reference case.

PLENTICORE plus 5.5: high efficiency, powerful performance

In the 5 kW class, the PLENTICORE plus 5.5 with BYD Battery Box HVS 7.7 was able to demonstrate its fantastic efficiency. It finished in a strong 3rd place with a brilliant performance, enabling the system to assert itself once again with a high ranking in its 5th year of grading.

The DC-coupled PLENTICORE-BYD combination achieved an excellent inspection result with an SPI of 91.2 percent. The main reason for this fantastic result is the improved control dynamics achieved through software optimisation, which had a positive lasting effect on the overall result. The high efficiency of the inverter and high-voltage battery deliver a consistently strong performance as an overall system.

The storage inspection confirms that PLENTICORE plus 5 kW ranks among the top 3 in this power class.

PIKO MP plus: great cost-effectiveness in the overall system

A strong player in DC and AC operation: the single-phase PIKO MP plus 4.6-2 with BYD storage HVS 7.7 demonstrated what it is capable of in every respect, achieving high efficiency values with an SPI of 90 percent (DC) and 89.6 percent (AC) – even in a small power class.

In addition to the high efficiency levels, the good inverter efficiency, the fast settling time and the low control losses are key to the all-round cost-effective performance of the overall system.

The outstanding performance of the PIKO MP plus was put it in second place and proves that it reliably boosts the cost-effectiveness of PV systems in the overall evaluation of all AC-coupled systems in the 5 kW reference case.

Summary: With the PLENTICORE plus as an outstanding hybrid inverter, the PLENTICORE BI as a powerful battery inverter in the three-phase connection range and the PIKO MP plus as a single-phase all-round inverter, KOSTAL customers consistently benefit from high solar yields and storage performance.

A brief explanation: What is the System Performance Index (SPI)?

Every year, the solar storage systems research group at HTW Berlin compares the system properties of photovoltaic systems on the basis of test reports provided by independent measurement laboratories.

In accordance with efficiency guidelines, the storage systems are tested using simulations and graded with what is known as the SPI.

For inverters in the 5 kW and 10 kW power classes, two reference situations were used to gauge the devices: in the first variant, a 5 kWp solar system with a home consumption of 5010 kWh per year was tested. The second variant included a system set-up with the same home consumption, operation of a 10 kWp solar system, supplying 2664 kWh a year to a heat pump and an electric car with an annual consumption of 1690 kWh.

For KOSTAL, the PLENTICORE plus inverter in the 5.5 and 10 kW power classes, the PLENTICORE BI 10/26 battery inverter and the PIKO MP plus 4.6-2 in combination with BYD battery boxes all took part in the storage inspection. HTW Berlin tested a total of 21 system solutions from 14 manufacturers.

KOSTAL provides the most flexible solutions among all participants: both AC and DC systems as well as single- and three-phase devices.