KOSTAL Pressebereich


2024 storage inspection: the results are in

KOSTAL’s PLENTICORE plus G2 inverter enters its first storage inspection in 2024

For the seventh time in a row, KOSTAL has undergone the independent storage inspection by HTW Berlin. Here the KOSTAL inverters demonstrated their full potential in combination with connected battery storage systems. In addition to storage systems from BYD, solutions from Dyness and Pylontech were included in the storage inspection for the first time. The second-generation KOSTAL PLENTICORE plus inverter (available since 2023) also made its début.

All the results at a glance:

  • Efficiency class A for KOSTAL PLENTICORE plus G2 10 and BYD HVS 12.8 (94.9%)
  • Best 3-phase AC storage system for KOSTAL PLENTICORE BI G2 10/26 and BYD HVS 12.8 (94.3%)
  • KOSTAL PLENTICORE plus G2 5.5 and BYD HVS 7.7 ranked in the top three (92.3%)
  • KOSTAL PLENTICORE plus G2 10 and Pylontech Force H2 (94.4%) in the top ten – on their first participation
  • KOSTAL PLENTICORE plus G2 10 and Dyness Tower T14 (94.2%) in the top ten – on their first participation
  • Only KOSTAL has AC and DC systems for single-phase and three-phase solutions.
  • Only KOSTAL has a wide selection of compatible battery partners.

The AutoUpdate function gives existing KOSTAL customers retroactive and automatic benefits.

HTW Berlin’s 2024 storage inspection

HTW Berlin’s 2024 storage inspection

Participating in the performance survey for the seventh time, KOSTAL once again demonstrated the impressive interaction between KOSTAL inverters and appropriate battery storage systems. 

KOSTAL customers benefit particularly in terms of system flexibility as KOSTAL has both AC and DC systems as well as single-phase and three-phase solutions.

KOSTAL also offers its customers a wide selection of compatible battery partners.

TIP: For existing customers with the PLENTICORE plus hybrid inverter and PLENTICORE BI battery inverter, the standard AutoUpdate function provides retroactive, automatic and free benefits.

Simply activate AutoUpdate in the inverter and you will always receive the latest software version – for maximum safety and efficiency.

All KOSTAL results at a glance:

KOSTAL inverters with efficiency class A
KOSTAL inverters with a DYNESS storage system in the test
KOSTAL inverters with a PYLONTECH storage system in the test

PLENTICORE plus 10 kW G2: the all-round hybrid inverter

In combination with the BYD Battery Box HVS 12.8 storage system, the hybrid inverter achieved a System Performance Index (SPI) of 94.9%. With low control and dimensioning losses, the usable storage capacity of 12.3 kWh was efficiently available.

In conjunction with the Pylontech H2 storage system, it achieved an SPI of 94.4%. With low control and standby losses, a high and rapid availability of the storage capacity of 14.21 kWh was guaranteed.

In combination with the Dyness T14 storage system, the hybrid inverter achieved an SPI of 94.2%. With very moderate conversion, standby and control losses, the system quickly and efficiently makes 14.2 kWh of battery capacity available for use.

These results show that the PLENTICORE plus G2 in combination with a battery storage system is suitable for high to very high efficiency requirements – making it one of the best devices on the market.

PLENTICORE plus 5.5 kW G2: the efficient hybrid inverter

The PLENTICORE plus 5.5 kW G2 hybrid inverter achieved an SPI of 92.3% with the BYD Battery Box HVS 7.7 storage system. With low dimensioning and conversion losses, high device readiness and fast control, the PLENTICORE delivers a battery efficiency of over 96%.

This level of performance makes the inverter one of the three best devices in the test and – with a slight increase in performance and optimised control dynamics – confirms its leading position in the field.

The storage inspection has shown that the second generation of the hybrid inverter, too, lives up to its promises. The PLENTICORE plus G2 ranked among the top three in its power class, continuing the outstanding results of the previous generation.

PLENTICORE BI 10 kW/26 G2: the high-performance battery inverter

The 10 kW 26 A version of the second-generation PLENTICORE BI 10 kW/26 delivered impressive results in the storage test. Combined with a BYD Battery Box Premium HVS 12.8, it achieved an SPI of 94.3%. The AC system thus improved its performance by 0.3% over the previous generation.

The storage inspection therefore confirmed the KOSTAL battery inverter's excellent efficiency and showed once again that the PLENTICORE BI and a suitable BYD storage system make a top duo for fast charging and discharging. With a capacity of 12.8 kW, this combination offers high storage reserves for high self-consumption.

The KOSTAL-BYD combination also offers high efficiency, minimal losses and efficient control during charging. With a discharge power of 10 kW, the usable battery capacity is fed into consumption extremely quickly. Almost all of the battery's capacity is fed back into the domestic power grid, as the PLENTICORE BI has a high conversion efficiency of 96%.

In the 2024 storage inspection tests, the PLENTICORE BI 10/26 stood out as a three-phase battery inverter among the AC coupling systems in the 10 kW power range and took first place.

2024 storage index: in conclusion

In their second generation, KOSTAL inverters – both alone and in combination with battery partners – are once again demonstrating all the company’s expertise. With both the PLENTICORE plus hybrid inverter and the powerful PLENTICORE BI battery inverter, customers benefit flexibly and based on their needs from both AC- and DC-coupled systems. 

About the storage inspection

In the 2024 storage inspection, HTW Berlin, an independent institute funded by the German Federal Ministry for Economic Affairs and Climate Action, analysed 20 systems from 14 manufacturers in the PV market. The tests were carried out strictly in accordance with the efficiency guidelines for PV systems. The resulting System Performance Index (SPI) indicates the efficiency level of a PV system of inverters combined with storage systems. HTW firstly examines the 5 kW power range for supplying household electricity at 5010 kWh/year and secondly the 10 kW range for providing 5010 kWh/year for the building, plus supplying a heat pump and an electric vehicle.