Kostal launches 25 kW battery inverter for large storage

A large battery cabinet is only useful if its electronics can move energy at the right scale. Kostal’s answer is the 25 kW Plenticore BI 25, a three-phase, AC-coupled battery inverter launched for commercial installations and high-end residential buildings. It supports storage systems from 5 kWh to 230 kWh, according to pv magazine.

AC coupling means the battery has its own inverter rather than sharing the solar inverter. That lets installers size the storage system independently. Kostal says three independent battery connections can accommodate high-voltage batteries, including its modular Helivor HV system, while the separate units can potentially shorten DC cable runs by placing the battery inverter close to the solar array.

The inverter is designed to do more than store surplus solar power. It can use dynamic electricity tariffs to decide when to charge or discharge, and it provides three-phase backup power for loads of up to 25 kVA. Kostal specifies a peak efficiency of 98.3% and says standby losses are low. The unit can be paired with the company’s Piko CI G commercial photovoltaic inverters, offered in 30 kW, 50 kW and 100 kW versions.

So what changes in practice? Specialist planners, installers and operators get a single battery inverter aimed at larger on-site storage projects, peak-load reduction and solar self-consumption. Kostal’s Multi Device Control can coordinate several inverters and connect them to building or energy-management systems through EEBus and Modbus/SunSpec TCP. The system can also be commissioned through an app, web server or the inverter itself, with automatic firmware updates and monitoring through Kostal’s app and portal.

The regulatory layer is part of that control environment: Kostal says Multi Device Control supports signals required under Sections 9 and 14a of Germany’s energy laws. The product’s reported efficiency and capacity range come from the manufacturer, while the launch information does not establish independent performance in field conditions.