Second-life energy storage systems (ESS) represent an important milestone in sustainable energy supply. They utilize refurbished or repurposed batteries to offer a cost-effective and environmentally friendly storage solution, which is becoming increasingly significant for both private households and commercial applications. These systems are crucial for bridging the gap between energy generation and consumption, significantly contributing to the stability and efficiency of the power grid.

The energy storage system was designed in collaboration with ZM3 for Horst Zimmermann in Göfis, Vorarlberg, and integrated into a private building known as "Sonnenhaus 2.0." Here, a battery storage system is used in combination with a photovoltaic (PV) system to optimize the self-consumption of solar power. The key to the efficiency of this project lies in storing the excess energy produced by the PV system. The installed standalone battery storage system, with a capacity of 260 kWh and a power output of 67.5 kW, allows the homeowner to achieve greater independence from external energy sources while maximizing the use of renewable energy.